Jason Teven and James Katt

8Instructor Credibility

Abstract: For centuries scholars have believed source credibility to be one of the central elements of persuasive communication. Aristotle envisioned ethos or credibility as an audience’s image of a particular source and suggested that it was the most potent means of persuasion. During the 1960s, communication scholars advanced empirically based approaches to the study of Aristotle’s theory of ethos. Students make attributions about an instructor’s credibility based on that instructor’s communication behavior. Instructor credibility – perceived character, caring, and competence – has emerged as a super-variable that affects teacher-student interactions and instructional outcomes. In this chapter we trace the genesis of ethos/ credibility back to ancient Greece and summarize both early and contemporary social scientific work on source credibility, including operationalizations of the multi-dimensional construct. We review instructor characteristics that are positively or negatively associated with student perceptions of credibility and identify some demographic variables associated with instructor credibility. We conclude by considering theoretical and pedagogical implications of credibility across cultures, discussing possibilities for extending future research, and providing some research-based practical suggestions for instructors.

Keywords: ethos, credibility, instructor characteristics, competence, character, goodwill, caring, trust, source, attribution, Aristotle

Twenty-five hundred years ago, long before anyone dreamed of printing presses, telephones, television, or texting, oratory was the primary mode of public communication. Ancient Greece was a culture in which laws and societal issues were debated and decided orally, and the most effective orators usually had the most influence. Aristotle (trans. 1932), a student of Plato and a skillful observer of human interaction, identified three types of appeals one might use when delivering a persuasive message: logos, logical appeals; pathos, emotional appeals; and ethos, source credibility.

Aristotle espoused that the source of a message is a dominant factor in that message’s persuasiveness. He observed that the source of communication can have a tremendous influence on how an audience receives a message, and the findings of contemporary scholars bear this out. Simply put, people often reject information from sources that lack credibility (Beatty & Behnke, 1980). Research has shown that the effectiveness of a persuasive message is partly dependent upon the receivers’ perceptions of credibility of the source (Burgoon, 1976; Hovland, Janis, & Kelley, 1953; McCroskey, Holdridge, & Toomb, 1974; Miller & McReynolds, 1973). Higher audience attributions of source credibility correlate with greater persuasive effectiveness (McCroskey & Teven, 1999).

The study of ethos, or credibility, has a long and rich history. Credibility is arguably the most studied construct across contexts within the human communication discipline, and more than four decades of research have been devoted to understanding credibility in instructional communication settings. As will become evident in this chapter, credibility can be considered an instructional communication super-variable because it is related to so many other instructional communication variables. McCroskey and his colleagues (1974) were the first to argue the importance of credibility for instructors in the classroom and to recognize its power to influence student learning outcomes.

In this chapter we trace the genesis of ethos/ credibility back to ancient Greece and summarize both early and contemporary social scientific work on source credibility, including operationalizations of the multi-dimensional construct. We review instructor characteristics that are positively or negatively associated with student perceptions of credibility and identify some demographic variables associated with instructor credibility. We conclude by considering theoretical and pedagogical implications of credibility across cultures and discussing possibilities for extending future research.

Conceptual Foundations and Developmental Research

Ethos, or credibility, was a major focus of theorizing and discussion in ancient Greece and Rome. For example, Aristotle (trans. 1932) viewed credibility as an audience’s image of a particular source and suggested that it was the most potent means of persuasion. Aristotle’s assertions have been corroborated by modern scholars whose research suggests that a speaker perceived to have high credibility tends to be more persuasive (O’Keefe, 2015; Stiff, 1986), and is seen as a more effective communicator (Infante, 1985), than a speaker with low credibility. Aristotle asserted that communicators must establish their credibility from the very beginning of a communication act because the receivers’ positive perceptions of the source can enhance the persuasiveness of that message. Thus, credibility is a dynamic construct: it is subject to change as a result of experiences that an audience has with a particular source (McCroskey, 1968).

Source credibility is a multidimensional construct. Aristotle’s conceptualization of credibility is reflected in three primary dimensions: intelligence (sagacity and good sense), trustworthiness (good moral character), and goodwill. Intelligence consists of one’s possessing knowledge or expertise of a particular subject. Corax and Tisias (400 B.C.) essentially developed the study of communication, teaching effective persuasive speaking to citizens who needed to use these skills in courts to settle land disputes (Kennedy, 1999). They were already providing the foundation for the type of communication competence that Aristotle would call intelligence. If sources are to be perceived as intelligent, they must be perceived to know what they are talking about. Perceptions of intelligence depend both on one’s actual expertise and how that expertise is portrayed or communicated. Competent communicators explain complex material clearly, possess above-average communication skills, and have the ability to answer audience questions effectively. The essential question for listeners is, “Do we perceive this person to be an authority who speaks knowledgeably about the subject at hand?”

The second dimension of source credibility is trustworthiness. Trust is a foundation of credibility and can influence attitude change (Giffin, 1967). Aristotle stated that audiences are more likely to believe people who have good character than those who do not.

Persuasion is achieved by the speaker’s personal character when the speech is so spoken as to make us think him [sic] credible. We believe good men more fully and more readily than others: this is true generally whatever the question is, and absolutely true where exact certainty is impossible and opinions are divided … his [sic] character may almost be called the most effective means of persuasion he possesses. (Aristotle, trans. 1932, pp. 8–9)

The trustworthiness dimension is at the heart of the credibility construct. Within a relationship, even one in the public communication arena (speaker-audience), trustworthiness is the degree to which an audience member trusts a speaker or source. When audience members perceive that a speaker is not being truthful, they are likely to see that speaker as less credible.

Goodwill, the third component of source credibility, has to do with the receivers’ perceptions of the speaker’s intentions toward them. Speakers who communicate goodwill demonstrate that they have their audiences’ best interests at heart. For instance, politicians often speak to the issues that concern voters the most. Speakers who communicate that they care about their audiences (more than their own selfish interests) will be perceived as more credible. Hence, credibility is not only based on positive qualities of a source, but also on the relationship a speaker builds with an audience through acts or expressions of goodwill.

The brilliance of Aristotle’s conception of credibility is that it is audiencebased. Speakers do not possess credibility by themselves; rather, their credibility lies in the perception of the audience. It is important for speakers to learn how to communicate in such a manner that their audience members will attribute to them the quality of credibility. As Teven and McCroskey (1997) asserted, “It is not the caring that counts; it is the perception of caring that is critical” (p. 1). As recipients and evaluators of the message, it is the audience who ultimately makes the assessment of source credibility, and in the classroom it is students who assess the credibility of their instructor.

Other notable rhetoricians also placed importance on the integrity of the speaker in communication. Quintilian emphasized credibility in his reference to “a good man speaking well” (Murphy, 1983, p. 156). He described the ideal Roman orator as one who is “virtuous, efficient, courageous, eloquent” (Murphy, 1983, p. 175). Isocrates, a contemporary of Aristotle, also considered the speaker’s credibility in the persuasion process. Specifically, Isocrates discussed a speaker’s prior reputation, which must be established and developed over time, to be more important than substance or content of the rhetorical discourse. As Isocrates stressed in Antidosis (trans. 1929), “The man who wishes to persuade people will not be negligent as to the matter of character; no, on the contrary he will apply himself above all to establish a most honorable name among his fellow citizens” (p. 339). Cicero advanced Aristotle’s theory of credibility by suggesting that word choice and speaking style affect an audience’s perceptions of the speaker’s character (Smith, 2012).

Early Social Scientific Work on Source Credibility

The role of source credibility in communication has been studied extensively for several decades (Andersen & Clevenger, 1963; Berlo, Lemert, & Mertz, 1971; Hewgill & Miller, 1965; Hovland et al., 1953; McCroskey, 1966; McCroskey & Dunham, 1966; McCroskey & Young, 1981; Miller & Hewgill, 1964; Self, 1996). Overall, research has shown that the effectiveness of a persuasive message is partly dependent upon the receiver’s perceptions of credibility of the source (Burgoon, 1976; McCroskey et al., 1974; Miller & McReynolds, 1973). Early experimental results in psychology revealed unequivocal evidence of the positive relationship between the credibility of the communicator and attitude change (Arnet, Davidson, & Lewis, 1931; Aronson, Turner, & Carlsmith, 1963; Bochner & Insko, 1966; Haiman, 1949; Hovland & Weiss, 1952; Kelman & Hovland, 1953; Kulp, 1934).

An important program of research on source credibility and attitude change was developed at Yale University (Hovland et al., 1953; Hovland & Weiss, 1952). As an extension of Aristotle’s three elements of intelligence, character, and goodwill, Hovland et al. saw source credibility as composed of three elements: expertness, trustworthiness, and intention toward the receiver. Various other writers have used different terms, but generally theorists have agreed there is a dimension that can be referenced as competence (qualification, expertness, intelligence, authoritativeness) and another dimension that can be referenced as trustworthiness (character, sagacity, safety, honesty). The third dimension, goodwill or intention toward receiver, was for decades the “lost dimension” of credibility due to misanalysis and/or misinterpretation of data in a variety of empirical studies. As a result, this dimension was ignored by many contemporary researchers and theorists until the 1960s.

The Factor Analytic Revolution

From the mid-1960s to the early 1980s, scholars utilized factor analysis to test Aristotle’s original conceptualization of source credibility, investing considerable effort in the development of valid instruments to measure the construct (Applbaum & Anatol, 1973; Baudhuin & Davis, 1972; Berlo et al., 1971; Falcione, 1974; McCroskey, 1966; McCroskey & Jenson, 1975; McCroskey & Young, 1981; Tuppen, 1974; Whitehead, 1968). Most of these researchers accepted the traditional three-dimensional conceptualization, but some conducted purely exploratory studies to determine through factor analysis the exact number and identity of dimensions. In most of these studies dimensions that could be labeled competence and trustworthiness (or similar titles) were observed, but none adequately identified a third dimension that could be appropriately labeled goodwill or intent toward receiver.

The goodwill dimension had always been included in the theoretical discussion, but decades of research into general person perception based on the meaning measurement approach (Osgood, Suci, & Tannenbaum, 1957) had taken the emphasis away from the theory-based examination of credibility (Cronkhite & Liska, 1976), which led to a myriad of new dimensions of credibility being “discovered.” Unfortunately, this approach only added confusion to the understanding of credibility. McCroskey and Young (1981) observed that, when subjected to factor analytic techniques, only two dimensions of credibility survived, with the third (goodwill) being subsumed under the other two dimensions. This was due to the fact that satisfactory measures of competence and trustworthiness had been developed, but not for goodwill. The resulting effect was that goodwill, as a component of the larger source credibility construct, was frequently overlooked or omitted from contemporary communication research.

After a careful reconceptualization and operationalization of the goodwill dimension, two studies (Teven & McCroskey, 1997; McCroskey & Teven,1999) reexamined the source credibility construct, particularly the goodwill dimension. To operationalize the three-dimensional credibility construct asserted earlier by Aristotle, they used a 10-item bipolar scale that included a distinct goodwill (or perceived caring) dimension. They found that students’ perceptions of the caring of their teachers was independent of their other credibility perceptions (competence and trustworthiness) as confirmed by factor analysis. Moreover, those perceptions of caring predicted unique variance in teacher evaluation, affective evaluation of the content of the course, and student perceptions of their cognitive learning. Furthermore, after removing the variance predicted by competence, trustworthiness, or the two combined, analysis indicated a substantial proportion of the variance in each of the dependent variables was uniquely predicted by perceived caring.

To replicate these findings outside the instructional context, McCroskey and Teven (1999) examined political sources, public sources, and interpersonal sources. Employing confirmatory factor analysis, they found further support for the traditional three-dimensional construct, as well as for the reliability and validity of the new goodwill/perceived caring measure. They developed and further refined the scale by measuring each dimension of credibility with six bipolar adjective items. The resulting 18-item measure, which is in use today, assesses the three dimensions of competence, trustworthiness, and perceived caring. Although each dimension contributes unique variance to the construct, they are all correlated with each other.

Goodwill/Perceived Caring

Caring is a receiver perception, based on verbal and nonverbal behaviors of a source, that influences perceptions of credibility (Teven, 2001; Teven & Hanson, 2004). Within the instructional setting, a central perception of teachers made by students is the degree to which the teacher cares about them as individuals and as a class (McCroskey, 1992). Perceived caring, as discussed by Teven and McCroskey (1997), is similar to Aristotle’s conceptualization of a speaker’s goodwill toward an audience. Students often associate caring teachers with credible teachers (McCroskey, 1992). Caring teachers promote a climate of trust both within the classroom (Chory, 2007; Teven & Hanson, 2004) and in advisor-advisee interactions (Wrench & Punyanunt, 2004). In fact, Wrench and Punyanunt (2004) reported that graduate student advisees’ perceptions of their advisor’s caring/ goodwill alone accounted for nearly 40% of the variance in their perceptions of the effectiveness of the advisoradvisee relationship.

Three factors lead students to perceive the teacher as caring about their welfare: empathy, understanding, and responsiveness (McCroskey, 1992). Empathy is one’s ability to identify with another’s situation or feelings. Prosocial behavior stems from altruistic motives and a concern for others (Stiff, Dillard, Somera, Kim, & Sleight, 1988). The second factor of teacher caring is understanding, or the ability to comprehend another person’s ideas, feelings, and needs. Perceived understanding has a positive impact in a variety of communication contexts (Cahn, 1986; Cahn & Shulman, 1984; Cushman & Cahn, 1985). Some teachers are adept at determining when students are encountering a problem either personally or with the course content, whereas other teachers seem insensitive to such matters. Responsiveness, the third factor of perceived caring, involves being other-oriented and having sensitivity toward others. The responsive individual is defined as ‘‘helpful, sympathetic, compassionate, sincere, and friendly’’ (Thomas, Richmond, & McCroskey, 1994, p. 109). Students typically evaluate teachers based on how they communicate caring (empathy, understanding, and responsiveness), and teachers who are perceived to communicate caring are also perceived as credible.

Students’ attitudes toward their instructors are integral to important learning outcomes, and it is in the context of instructional communication that credibility emerges as a super-variable. In the classroom, the instructor is a central figure and the primary source of messages and information. If students do not place trust in their instructors, they may not make sufficient investment in the relationship or in the learning process and may even question the relevance or validity of the information their instructors present. On the other hand, positive perceptions of instructor credibility are associated with higher reports of student motivation (Jaasma & Koper, 1999; Martin, Chesebro, & Mottet, 1997) and various learning outcomes (Beatty & Zahn, 1990; Pogue & AhYun, 2006; Teven & McCroskey, 1997), especially the affective component consisting of positive regard for the instructor and the material presented in the course (Krathwohl, Bloom, & Masia, 1964). A recent meta-analysis conducted by Finn and colleagues (2009) explored the relationships among instructor credibility, instructor behaviors and traits, and student outcomes in over 50 independent studies. They concluded that, although overall instructor credibility plays a substantial role in both creating effective instructor-student interpersonal relationships and enhancing student learning, it is the caring dimension that is the most salient of the three dimensions from the students’ perspective. In the American college classroom, instructors show their caring for their students in five ways: (1) they behave in ways that demonstrate their concern for student performance and/ or grades; (2) they are concerned about their own teaching and classroom performance; (3) they solicit, and respond to, student questions and feedback; (4) they attempt to build positive interpersonal relationships with their students; and (5) they use nonverbal immediacy behaviors while teaching (Teven & Gorham, 1998). Teachers who exhibit these values and communicating styles are deemed as credible sources of course information.

Instructor Characteristics and Actions Associated with Credibility

Instructional communication scholars have identified a number of instructor characteristics and behaviors associated with students’ attributions of instructor credibility, as well as characteristics or misbehaviors that may decrease those perceptions. For example, Mazer and Graham (2015) investigated instructors’ immediacy and clarity in relation to credibility and reported positive correlations among the three variables. Other scholars have studied additional instructor variables in relation to perceptions of credibility. We briefly summarize their findings here.

Nonverbal Immediacy

Mehrabian (1969, 1971) originally advanced the immediacy concept in the interpersonal domain of communication. He defined immediacy as behaviors that “enhance closeness to and nonverbal interaction with another” (Mehrabian, 1969, p. 213). Andersen (1979) identified the nonverbal communication cues that increase perceptions of interpersonal closeness (immediacy) between teachers and students, including eye contact, gestures, relaxed body position, smiling, vocal expressiveness, movement, and proximity. Numbers of research studies have shown that teachers who engage in these communicative actions are perceived by their students as more credible than those who do not (e.g., Teven & Hanson, 2004), probably because these actions indicate caring and positive personal regard.

Affinity Seeking

Affinity seeking is “the process by which individuals attempt to get other people to like and feel positive towards them” (Bell & Daly, 1984, p. 111). Teachers who employ more affinity-seeking strategies with students are perceived as more like-able and create a more positive classroom climate (Myers, 1995). Frymier and Thompson (1992) discovered positive relationships between instructor use of affinity-seeking behaviors and students’ perceptions of teacher competence and trustworthiness, two of the dimensions of credibility. Frymier and Thompson (1992) pointed out, however, that some of the affinity-seeking strategies appear to enhance perceptions of character (trustworthiness) but not perceptions of instructor competence. Hence, ongoing research programs will serve to clarify these discrepant findings.

Communicator Style

Norton (1978) defined communicator style as “the way one verbally and paraverbally interacts to signal how literal meaning should be taken, interpreted, filtered, or understood” (p. 99). An instructor’s communicator style affects the way he or she presents course content (Nussbaum, 1992). For example, Sallinen-Kuparinen (1992) suggested that teachers perceived to be friendly, relaxed, dramatic, attentive, and open communicators are also perceived to be effective teachers, especially capable of generating high affective evaluations for their courses. Rubin and Feezel (1986) observed that teacher credibility and teacher effectiveness were best predicted by the communication styles of being relaxed and impression-leaving. Beatty and Behnke (1980) found that instructors who were consistent in their verbal and nonverbal messages accompanied by positive vocal cues were often perceived as more competent and possessing greater character. In fact, Teven and Comadena (1996) discovered students’ perceptions of instructor communicator style and credibility were more positive if the instructor maintained an office that was generally neat, organized, and attractive.

Socio-Communicative Style

A related teacher variable, socio-communicator style (SCS), centers on perceptions of the patterns of an instructor’s communication behaviors. According to Thomas (1995), SCS refers to “an individual’s tendencies with regard to initiating communication with and reacting and adapting to the communication of another person” (p. 5). SCS is usually classified into two orthogonal dimensions: assertiveness and responsiveness. “Assertiveness is characterized by descriptors such as independent, dominant, aggressive, competitive, and forceful. Responsiveness is characterized by descriptors such as helpful, sympathetic, compassionate, sincere, and friendly” (Thomas et al., 1994, p. 109). Students’ perceptions of teacher communicator style are not often based on one single interaction, but rather a continuing pattern of interactions between both the students and a teacher. For example, an instructor who is assertive is willing to take a stand, to stand up for her or his position without impinging upon the rights of students to believe differently (Richmond & McCroskey, 1990). Kearney (1984) described a highly assertive teacher as one who strives for excellence and who sustains task orientation. Wooten and McCroskey (1996) found that student perceptions of increased teacher responsiveness and assertiveness were associated with increased trust of the teacher (both are positively related with trust, though the relationship was much stronger for responsiveness than for assertiveness). Scholars have also conceived of SCS along four categories (competent, aggressive, submissive, and noncompetent). Martin and colleagues (1997) found instructors with the SCS of competent were perceived highest in all three dimensions of credibility (expertise, character, and caring) and in students’ situational motivation. Conversely, instructors classified as noncompetent were perceived as lowest in caring and expertise, and instructors classified as aggressive were perceived as lowest in character.

Teacher Power Use

Power can be conceived as the behavioral patterns and verbal and nonverbal message strategies used by a source in order to maximize the impact upon the targets of a persuasive attempt (McCroskey, 1998). In an instructional context, perceived power refers to “the degree to which the student perceives the teacher as having the ability to influence the student’s existence” (Hurt, Scott, & McCroskey, 1978, p. 125). The use of power is an inherent part of the teaching process (McCroskey & Richmond, 1983); if teachers do not exert influence in the classroom, they are not likely to enhance student learning (Richmond & McCroskey, 1984; Richmond & Roach, 1992).

College instructors have drawn from a number of traditional power bases, including reward, referent, expert, coercive, and legitimate strategies (French & Raven, 1959), to influence students to follow course policies, attend class, and complete tasks. Instructor influence strategies (whether prosocial or antisocial in nature) can affect students’ perceptions of credibility and satisfaction in the college classroom. Teven and Herring (2005) observed that students’ perceptions of their teachers’ expert, referent, and reward power use were positively related to their perceptions of their teachers’ competence, caring, and trustworthiness. Moreover, teacher power use predicted approximately one-third of the variance in teacher credibility (Teven & Herring, 2005). These results reflect the critical role of students’ perceptions of teacher power use in the classroom that may, in turn, mediate various perceptions of credibility. For instance, one study found that graduate teaching associates who employed more negative or antisocial strategies tended to damage their credibility with students (Pytlak & Houser, 2014).

Verbal Aggressiveness

Verbal aggressiveness involves communication behaviors that attack the self-concept of others (Infante, 1985; Infante & Wigley, 1986) and is sometimes considered a subset of hostility (Infante, 1987). By attacking a person’s self-concept and delivering psychological pain, verbal aggression has great impact on targets, leading to feelings of embarrassment, inadequacy, humiliation, hopelessness, desperation, and depression (Infante, 1987; Infante & Wigley, 1986). Research consistently suggests that verbal aggression leads to negative relational outcomes (Infante, Myers, & Buerkel, 1994; Infante & Rancer, 1996; Teven, Martin, & Neupauer, 1998; Venable & Martin, 1997).

In the instructional context, Teven and Gorham (1998) found that teachers who used direct verbal expressions of discouragement and/ or dislike towards their students were perceived to be significantly less caring than instructors who displayed empathy and who responded positively to students. Martin, Weber, and Burant (1997) reported that instructors who used verbally aggressive messages were perceived by students as less competent, less immediate, and less appropriate than those who did not use verbal aggression. Instructors’ use of verbally aggressive messages toward students is negatively associated with student affect toward the instructor, course, and recommended course behaviors (Myers & Knox, 1999). Teven (2001) reported that teacher verbal aggressiveness is negatively associated with student perceptions of their teachers’ caring, and Myers’ (2001) found that perceived instructor competence, trustworthiness, and caring were all negatively correlated with perceived instructor verbal aggressiveness. In other words, teachers who use verbally aggressive messages (e.g., character attacks, competence attacks, background attacks, physical appearance attacks, malediction, ridicule, threats, swearing, inappropriate nonverbal emblems) are perceived as being less competent and less caring than teachers who refrain from verbally aggressive communication with students.

Clarity

Chesebro and McCroskey (1998a) defined teacher clarity as a process that allows the instructor to “effectively stimulate the desired meaning of course content and processes in the minds of students through both verbal and nonverbal messages” (pp. 262–263). Clarity is a fundamental component of effective teaching (Chesebro, 2003). Eisenberg (1984) identified clarity as a relational variable because it requires the source to narrow the possible interpretations of a message so that the particular receiver may accurately interpret it. Early research found highly credible sources tended to use a clearer oral style than less credible sources (Carbone, 1975). Hence, a teacher who is clear (as compared to unclear) is likely perceived as credible by students. Research suggests that structure allows for clarity in the classroom (Chesebro & McCroskey, 1998b) and that nonverbal clarity includes time spent covering a topic, speaking pace, use of transitions, and clear communication of classroom process (Chesebro & McCroskey, 1998a, 1998b; Civikly, 1992). Teacher clarity leads to greater student achievement (Civikly, 1992; Sidelinger & McCroskey, 1997), which may, in turn, stimulate an increase in perceived teacher effectiveness (Sidelinger & McCroskey, 1997).

Teacher Misbehaviors

Instructor misbehaviors, by their nature, will harm students’ perceptions of credibility. Research on teacher misbehaviors has been directed toward identifying the behaviors of teachers that “interfere with instruction and thus, learning” (Kearney, Plax, Hays, & Ivey, 1991, p. 310). To identify specific teacher misbehaviors, participants were asked to recall instances when their teachers had said or done things that had ‘‘irritated, demotivated or substantially distracted them in an aversive way during a course’’ (Kearney et al., 1991, p. 313). This open-ended method generated over 1,700 teacher misbehaviors that aggregated into nine types of incompetence, six types of offensiveness, and six types of indolence, all of which lead to negative outcomes for both teachers and students. Teacher misbehaviors substantially reduced students’ affect and perceptions of teacher credibility (Banfield, Richmond, & McCroskey, 2006; Semlak & Pearson, 2008; Teven, 2007). It should be noted that instructors may be able to commit an occasional offensive misbehavior without experiencing a loss of credibility, as long as they remain interpersonally immediate with their students (Mottet, Parker-Raley, Beebe, & Cunningham, 2007).

Collectively, these research findings indicate that, though credibility is a student attribution about the instructor, teachers can proactively engage in certain communication styles and patterns that are likely to enhance more positive student perceptions. Before exploring theoretical explanations underpinning credibility research, we briefly note some important demographic variables that influence students’ perceptions of instructor credibility.

Demographic Variables and Perceived Credibility

Age

Semlak and Pearson (2008) observed that students perceive older teachers as more competent, caring, and trustworthy than younger teachers, though adult (non-traditional) learners may have different expectations of and standards for their instructors than younger, traditional students (Anderson, 1997). To account for this effect, Semlak and Pearson asserted that older teachers have had more life experience and have gained insight into why particular instructional techniques succeed or fail.

Gender and Biological Sex

Few studies in communication have addressed sex differences of students and faculty in relation to credibility, as there is little theoretical justification for assuming such differences. However, a few researchers have reported that female instructors are rated less credible than male instructors (Centre & Gaubatz, 2000; Hargett, 1999). This finding seems inconsistent with reports that female instructors are often rated higher in immediacy and thus are more likely to be seen as promoting closeness with students through their classroom behaviors (Jaasma & Koper, 2002), so future investigations are warranted.

Sexual Orientation

Russ, Simonds, and Hunt (2002) observed that students rated gay instructors as less credible than straight instructors and that they believed they learned more from heterosexual than homosexual instructors. With the passage of time since this study was conducted, and the changes in social attitudes in the United States, future studies may find discrepant results concerning this question.

Race

In the United States, racial differences have been more widely researched than other demographics. For example, Rubin (1998) reported that students rated Asian-American instructors as less credible and less intelligible than Caucasian instructors. Hendrix (1998) reported that, although students initially stated that they did not favor one race over the other, findings indicated that they perceived Black professors as harder-working when it came to establishing credibility. Concerned with more racially diverse populations, Glascock and Ruggiero (2006) found that White instructors were viewed as somewhat more competent and caring than their Hispanic colleagues, leading these researchers to conclude that increasing the numbers of faculty members of color could potentially enhance the perceptions of credibility of historically underrepresented faculty.

Theoretical Explanations of Instructor Credibility

Two established communication theories contribute explanations about how and why students perceive certain instructors as more credible than others. Expectancy violations theory (Burgoon & Hale, 1988) and attribution theory (Heider, 1958) are discussed in relation to the instructor credibility construct.

Expectancy Violations Theory

Students enter the classroom with expectations of how their instructors should interact, dress, communicate, and behave. As Witt and Wheeless (1999) explained, students bring a set of expectations about an instructor’s behavior derived from previous experiences with teachers. If a college instructor were to violate student expectancies, his or her credibility would likely be influenced as a result of violating expectations. For instance, if a male instructor were to use inappropriate touch with a female student in the classroom, student perceptions of his credibility are likely to be altered. Expectancy violations theory (EVT; Burgoon & Hale, 1988) explains that people experience increased arousal when others violate communication expectations. If an instructor deviates from what students expect, then an expectancy violation occurs. These violations can be emotionally unsettling for students. LePoire and Burgoon (1996) assert that arousal triggers an orienting response in which people shift attention away from the conversation to the other party (i.e., the violator) in an attempt to interpret and evaluate the unexpected behavior.

Researchers have examined the ways in which instructors have violated students’ expectations in the classroom (Lannutti, Laliker, & Hale, 2001; McPherson, Kearney, & Plax, 2003; Mottet et al. 2007). Applying the tenets of EVT to instructor credibility, when student expectations are met positively, students are more prone to like their instructors, perceive a closer relationship, and have more favorable attitudes toward and perceptions of their instructors (McPherson & Liang, 2007). Conversely, when students’ expectations for course instructors are violated, and such violations are deemed to carry a negative valence, students rate their instructors lower in credibility (Koermer & Petelle, 1991).

Mottet et al. (2007) examined the effects of teacher nonverbal immediacy behaviors and course-workload demands on student perceptions of teacher credibility and student affective learning. They concluded that immediate teachers preserved teacher credibility even when they violated student course-workload expectations. In other words, an immediate teacher who assigned a large course workload was perceived as more credible than the non-immediate teacher who assigned a large course workload. Returning to EVT, the positive communicator reward valence that students assigned to the immediate instructor tended to neutralize the way students perceived the instructor’s moderate and high workload demands. Thus, the tenets of EVT allow researchers to predict the effects of perceptual variables (e.g., immediacy) in relation to instructor credibility.

Attribution Theory

Attribution theory provides another lens through which to examine how people draw causal inferences about the source of the message (Heider, 1958; Kelley, 1967). Heider (1958) advanced a three-step process describing how individuals make attributions about the behavior of others, and this model explains how students make attributions about an instructor’s credibility based on that instructor’s communication behavior. First, students carefully observe their instructor’s behaviors in the classroom starting on the first day of class (Schrodt & Witt, 2006). As a simple example, students observe whether the instructor arrives early, on time, or late to class. Second, students begin to make judgments concerning their instructor’s behavior. For example, if the instructor were to habitually arrive late to class, students might attribute negative qualities of the instructor’s sense of professionalism and perceive the instructor to be less credible. Third, if students believe that their instructor has control over arriving on time to class (which is a fair and reasonable expectation since students made the effort to arrive to class on time), they will attribute dispositional (personal) characteristics to the instructor. All three dimensions of the instructor’s credibility (character, competence, and caring) could be negatively affected. Students would likely see the instructor as less trustworthy, given that instructors set the tone for the class. In addition, the instructor’s lateness creates an inconsistency: If instructors expect students to be on time, they too should arrive on time. Students might also interpret the instructor’s tardiness as an indication of lower competence or intelligence because the instructor failed to plan ahead and account for traffic or parking. Finally, students could perceive less goodwill/caring if they judged the instructor to be self-centered and concerned with neither the students nor excellent job performance. Such negative credibility attributions would likely have negative effects on student motivation and learning.

Theoretical and Pedagogical Implications

Credibility Across Cultures

Recently, scholars have begun to explore the question of generalizability of the source credibility construct across cultures beyond the instructional context (Dilbeck, Domínguez, Ruiz, McMurrich, & Allen, 2013; Santilli, Miller, & Katt, 2011). The extant credibility measures have mostly been tested within a Western (and monocultural) perspective and beg for valid assessments across cultures. Because participants from other cultures operate from a semantic space that is different from the Euro-American population, their attributions of source credibility could also be different. In other words, their meanings for credibility may or may not be accurately represented on commonly used credibility scales. Complicating the issue is the fact that varying conceptions and evaluations of credibility emerge from existing values of the culture in question. The world’s cultures have produce a wide variation of communication differences pertaining to the notion of “self” and “other” (Hofstede, 1983; Knutson & Posirisuk, 2006; Neuliep, 2009; Nisbett, 2003; Oetzel & Ting-Toomey, 2003; Oyserman, Coon, & Kemmelmeier 2002; Triandis, 1995). The majority of data already collected on teacher credibility comes from students taking courses in a U.S. classroom setting. It is likely that particular dimensions of the credibility measure (competence, trustworthiness, and/or caring) are more salient factors in some cultures than others.

In a cross-cultural investigation comparing students in the United States (low context) and Brazil (high context), Santilli et al. (2011) found that the U.S. students perceived instructor nonverbal immediacy behavior to be positively associated with all three dimensions of source credibility: competence, trustworthiness, and caring. Among Brazilian students, however, instructor nonverbal immediacy was positively related to competence and caring only. The relationship of nonverbal immediacy to instructor competence was stronger for Brazilian students than it was for U.S. students. Dilbeck et al. (2013) recently discovered that all three elements of credibility (competence, trustworthiness, and goodwill/caring) tend to generalize to Spanish and Thai cultures (Dilbeck et al., 2013). Employing structural equation modeling, Zhang (2009) tested a credibility-learning model in U.S., Chinese, German, and Japanese classrooms. She discovered that teacher credibility showed only an indirect relationship to cognitive learning, mediated by affective learning and motivation. Teacher competence and caring had a positive relationship with affective learning, while teacher trustworthiness had neither direct nor indirect association with affective learning, motivation, or cognitive learning. Interestingly, her confirmatory factor analysis indicated that the three-factor model of teacher credibility applied across the four cultural groups.

Implications for Teacher Training on Effective Intercultural Instruction

These findings suggest several implications for teacher training programs geared for cultural diversity and the enhancement of teacher credibility. Given that credibility is an audience perception and a prerequisite to being persuasive, effective intercultural teaching requires instructors to be adept in their audience adaptation. As Dilbeck et al. (2013) explain, “European and North American students often prefer more of an individualistic in-class dialectic to challenge and clarify what is taught, while Pacific/South(east) Asian students often prefer to seek clarity from the instructor outside of lectures as members of collectivistic groups” (p. 25). Imagine that an American instructor is invited to China as part of an international study abroad program, but the instructor is culturally insensitive, makes little attempt to adapt to the Chinese students, and does not adjust his/her classroom teaching style. This lack of awareness would likely cause damage to the instructor’s credibility with those students. Instructors who take the time to learn about specific culture(s) prior to placement in a school and who pay attention to their students’ unique learning styles, values, and affective and cognitive qualities, will have a better chance at establishing and maintaining credibility.

Directions for Future Research and Pedagogy

Scholars who wish to extend credibility research have a wide array of possible directions. For example, the availability of innovative instructional technologies offers new learning environments such as online courses, in-class pedagogy, and social networking systems, each of which may alter students’ perceptions of their instructor as a credible source of information. However, as future research programs are developed in this and other areas, it is imperative that scholars give greater attention to the validity of credibility measurement. We conclude the chapter by examining these future opportunities.

Perceptions of Instructor Credibility in Computer-Mediated Environments

Research has shown that perceptions of teacher immediacy and teacher credibility are highly correlated. However, online instruction often removes nonverbal cues and creates a greater sense of interpersonal distance, with the result that much of an instructor’s traditional classroom immediacy evaporates (Schutt, Allen, Laumakis, 2009; Trad, Katt, & Miller, 2014). The format of online classes presents a challenge to instructors in terms of engaging in nonverbal communication behaviors that enhance perceptions of affiliation, connection, and closeness. This limitation can be particularly problematic when instructors must critique their students’ work or give feedback concerning their performance. To compensate for the loss of relational cues, Trad et al. (2014) suggested that instructors engage in face threat mitigation (FTM) strategies when communicating potentially face-threatening messages (Kerssen-Griep, Trees, & Hess, 2008). How instructors provide instructional feedback to students can foster changes in the perceptions of how credible students evaluate that instructor to be (Witt & Kerssen-Griep, 2011). Extant research has indicated that FTM has positive effects on student affect and perceived instructor credibility (Kerssen-Griep & Witt, 2012; Sabee & Wilson, 2005; Trees, Kerssen-Griep, & Hess, 2009; Witt & Kerssen-Griep, 2011), but more work is needed to identify precise verbal strategies that reduce face threat and enhance positive perceptions of instructor caring and credibility. Can teachers be trained in the effective use of FTM tactics? Do traditional and non-traditional students differ in their expectations of instructor immediacy, or even credibility, in online environments versus face-to-face instruction? These and many other questions await careful investigation.

Classroom Instructors’ Use of Technology

Technology also enables the instructor to extend and enhance the student’s learning experience in the classroom (McComb, 1994), and technology use can have an effect on students’ perceptions of instructor credibility (Schrodt & Turman, 2005; Schrodt & Witt, 2006). Classroom technology such as videos, PowerPoint, and webbased resources have the potential to enhance student learning, and today’s college students enter the classroom expecting a certain amount of technology use during class. If instructors use too little or too much technology, is their credibility at risk? Early research indicates that it might be, as Schrodt and Witt (2006) reported that immediacy and technology use interacted to produce different levels of perceived credibility. Students perceived highly immediate instructors as being the most competent when they designed a course with minimal to moderate amounts of technology. Further study is needed to determine the most effective ways to introduce technology-assisted instruction during class times. Are there other communication cues or strategies that teachers can use to demonstrate their competence in the use of instructional technology? Are students’ expectations for technology use changing as new technologies become available? Do students view instructors as more competent or more credible if they appear to be early adopters of innovative technologies? Future researchers have many avenues to examine concerning technology in the classroom and its impact on perceived instructor credibility.

Perceptions of Credibility in Social Media

A current trend in college teaching is for instructors to bring social media into the classroom for the purpose of increasing student engagement and student participation (Powell & Powell, 2010). In addition, out-of-class sharing of personal beliefs through Facebook, Twitter, or social media sites has become increasingly popular. However, college instructors should be cautious how social media posts could impact their credibility. Early research findings indicated that as long as the content and interactions between students and instructor remained appropriate, an instructor’s credibility could be enhanced (Johnson, 2011; Mazer, Murphy, & Simonds, 2007), but rapid changes in technology are bringing rapid changes in social norms concerning the use and acceptance of social media. For example, more recent studies indicated that students’ perceptions of teacher credibility decreased as negativity of instructor self-disclosure increased (Coffelt, Strayhorn, & Tillson, 2014; Miller, Katt, Brown, & Sivo, 2014). With contradictory results being reported by researchers every day (e.g., Barberpp & Pearce, 2008; Hutchens & Hayes, 2014), it is imperative that credibility scholars closely examine teachers’ use of social media and the potential effects on perceptions of their credibility.

Measurement Issues

The majority of research studies on instructor credibility have employed Teven and McCroskey’s (1997) and McCroskey and Teven’s (1999) credibility scales to measure competence, trustworthiness, and goodwill. Though the reliability and validity of these scales have been well established since their introduction in the 1990s, models of instructional communication are growing increasingly complex. Furthermore, Mazer and Graham (2015) noted that “constructs evolve and measurement devices need to keep pace with this natural evolution” (p. 231), so future scholars should re-examine current credibility measures in the following ways:

Rhetorical Re-analysis

Because semantic differential scales are anchored by words, and the meanings of words are ever-changing, scholars should periodically subject scale anchors to lexical analysis to determine whether the meanings and connotations for the current anchors are still valid. If future students are unfamiliar with words that appear on the scales, the validity of certain scale items would be weakened (Teven & McCroskey, 1997).

Problems with Reverse-Coded Questions

It has been common practice among communication researchers to include reverse-coded items in multi-item scales. Traditional wisdom suggests including reversed items reduces the possibility that respondents develop a response pattern (Reinard, 2001; Wrench, Thomas-Maddox, Richmond, & McCroskey, 2013). Over the years, however, some scholars have pointed out potential confusion by respondents (Babbie, 2014, Reinard, 2008) due to negatively worded items. Others have examined the effects of including reversed items on the factor structure of multidimensional scales, noting a tendency for the reverse items, irrespective of their content, to load on the same factor (Deemer & Minke, 1999; DiStefano & Motl, 2006, 2009; Reinard, 2008). Although such an artifact might be of little consequence in a simple analysis, the emergence of a spurious method factor has the potential to confound a more complex analysis. Thus, future researchers should investigate the possibility of this type of measurement problem as they build and test complex statistical models.

Establishment of Best Statistical Practices

In his online instructions concerning the use of the McCroksey & Teven (1999) source credibility scales, McCroskey (2007) warned that “the three measures represent unique constructs, but those constructs are intercorrelated, as suggested by Aristotle … these scores should not be summed to create a single score” (McCroskey, 2007, para. 2). Despite his admonitions, some scholars still combine the individual scores into one. In addition, a variety of complex statistical models are being developed with little methodological consistency. For these reasons, future scholars should undertake methodological studies to determine best practices for statistical analysis of the three correlated, yet unique, credibility dimensions. The field can benefit from more credibility research, but only if it incorporates methodologies and measures that meet the most rigorous standards of scientific inquiry.

Advice to Teachers

Teachers provide leadership in the college classroom (Bolkan, Goodboy, & Griffin, 2011). From the initial meeting between the students and the instructor until the course ends, it is important for instructors to both establish and maintain the perception of credibility. When teachers engage in appropriate and effective classroom behavior, students are more prone to like them, perceive a closer relationship, and have more favorable attitudes toward and perceptions of their instructors. Cumulative research findings suggest four communication strategies for teachers seeking to establish and maintain credibility with students:

Conclusion

The ancient Greek and Roman rhetoricians correctly observed long ago that the credibility of the communicator can have a tremendous influence on the persuadibility of an audience. Modern research has since shown that instructor credibility is one of the most influential factors in determining the effectiveness of a classroom instructor. Although no single chapter can hope to cover all the ways in which teachers can influence students, we have sought to provide an overview of some of the most well-known, frequently-cited studies relating to instructor credibility. A strength of teacher credibility research is that it has yielded a wealth of useful, albeit qualified, generalizations, including empirical links between instructor characteristics, behaviors, and student perceptions of instructor competence, character, and caring. This is not to suggest that instructional communication scholars should consider the knowledge of credibility accrued thus far to be sufficient. With the accelerating rate of change in technology and culture, we can expect the next few years to bring new communication modalities, new communication challenges, and the necessity for new communication research that furthers our understanding of the ancient, yet contemporary, role of source credibility in instructional communication.

References

Andersen, J. F. (1979). Teacher immediacy as a predictor of teaching effectiveness. In D. Nimmo (Ed.), Communication yearbook 3 (pp. 543–559). Brunswick, NJ: Transaction.

Andersen, K., & Clevenger, T. Jr. (1963). A summary of experimental research in ethos. Speech Monographs, 30, 59–78.

Anderson, J. M. (1997). The effect of age and gender on students’ perceptions of valued college instructor characteristics and behaviors (Unpublished doctoral dissertation). Cornell University, Ithaca, NY.

Applbaum, R. L., & Anatol, K. W. (1973). Dimensions of source credibility: A test for reproductivity. Speech Monographs, 40, 230–237.

Aristotle (trans. 1932). The rhetoric of Aristotle (L. Cooper, Trans.). New York, NY: Appleton-Century-Crofts.

Arnet, C. C., Davidson, H. H., & Lewis, H. N. (1931). Prestige as a factor in attitude change. Sociology Social Research, 16, 49–55.

Aronson, E., Turner, J. A., & Carlsmith, M. L. (1963). Communicator credibility and communication discrepancy as determinants of opinion change. Journal of Abnormal and Social Psychology, 67, 31–36.

Babbie, E. (2014). The basics of social research (6th ed.). Belmont, CA: Cengage.

Baudhuin, E. S., & Davis, M. K. (1972). Scales of the measurement of ethos: Another attempt. Speech Monographs, 39, 296–301.

Banfield, S. R., Richmond, V. P., & McCroskey, J. C. (2006). The effect of teacher misbehaviors on teacher credibility and affect for the teacher. Communication Education, 55, 63–72. doi:10.1080/03634520500343400

Barber, L., & Pearce, K. (2008, May). The effect of instructor Facebook participation on student perceptions of teacher credibility and teacher attractiveness. Paper presented at the annual meeting of the International Communication Association, Montreal, Canada.

Beatty, M. J., & Behnke, R. R. (1980). Teacher credibility as a function of verbal content and paralinguistic cues. Communication Quarterly, 9, 55–59.

Beatty, M. J., & Zahn, C. J. (1990). Are student ratings of communication instructors due to “easy” grading practices?: An analysis of teacher credibility and student-reported performance levels. Communication Education, 39, 275–282.

Bell, R. A., & Daly, J. A. (1984). The affinity-seeking function of communication. Communication Monographs, 51, 91–115. doi:10.1080./036337758409390188

Berlo, D. K., Lemert, J. B., & Mertz, R. J. (1971). Dimensions for evaluating the acceptability of message sources. Public Opinion Quarterly, 33, 563–576.

Bochner, S., & Insko, C. (1966). Communication discrepancy, source credibility, and opinion change. Journal of Personality and Social Psychology, 4, 614–21.

Bolkan, S., Goodboy, A. K., & Griffin, D. J. (2011). Teacher leadership and intellectual stimulation: Improving students’ approaches to studying through intrinsic motivation. Communication Research Reports, 28, 337–346. doi:10.1080/08824096.2011.615958

Burgoon, J. K. (1976). The ideal source: A re-examination of credibility measurement. Central States Speech Journal, 27, 200–206.

Burgoon, J. K., & Hale, J. L. (1988). Nonverbal expectancy violations: Model elaboration and application to immediacy behaviors. Communication Monographs, 55, 58–79.

Cahn, D. D. (1986). Perceived understanding, supervisor-subordinate communication, and organizational effectiveness. Central States Speech Journal, 37, 19–26.

Cahn, D. D., & Shulman, G. M. (1984). The perceived understanding instrument. Communication Research Reports, 1, 122–125.

Carbone, T. (1975). Stylistic variables as related to source credibility: A content analysis approach. Speech Monographs, 42, 99–106.

Centre, J. A., & Gaubatz, N. B. (2000). Is there gender bias in student evaluations of teaching? Journal of Higher Education, 71, 17.

Chesebro, J. L. (2003). Effects of teacher clarity and nonverbal immediacy on student learning, receiver apprehension, and affect. Communication Education, 52, 135–147. doi:10.1080/03634520302471

Chesebro, J. L., & McCroskey, J. C. (1998a). The development of the teacher clarity short inventory (TCSI) to measure clear teaching in the classroom. Communication Research Reports, 15, 262–266.

Chesebro, J. L., & McCroskey, J. C. (1998b). The relationship of teacher clarity and teacher immediacy with students’ experiences of state receiver apprehension. Communication Quarterly, 46, 446–456.

Chory, R. M. (2007). Enhancing student perceptions of fairness: The relationship between instructor credibility and classroom justice. Communication Education, 56, 89–105. doi:10.1080/03634520600994300

Civikly, J. M. (1992). Clarity: Teachers and students making sense of instruction. Communication Education, 41, 138–152.

Coffelt, T. A., Strayhorn, J., & Tillson, L. D. (2014). Perceptions of teachers’ disclosures on Facebook and their impact on credibility. Kentucky Journal of Communication, 33, 25–43.

Cronkhite, G., & Liska J. (1976). A critique of factor analytic approaches to the study of credibility. Communication Monographs, 43, 91–107.

Cushman, D., & Cahn, D. D. (1985). Communicating in relationships. New York, NY: SUNY Press.

Deemer, S. A., & Minke, K. M. (1999). An investigation of the factor structure of the teacher efficacy scale. Journal of Educational Research, 93, 1–10.

Dilbeck, K. E., Domínguez, A., Ruiz, J. D., McMurrich, M., & Allen, M. (2013). Instructor credibility: A cross cultural examination. In Joan E. Aitken (Ed.), Cases on communication technology for second language acquisition and cultural learning (pp. 24–57). Hershey, PA: Information Science Reference, IGI Publishing. doi:10.4018/97814666-4482-3.ch006

DiStefano, C., & Motl, R. W. (2006). Further investigating method effects associated with negatively worded items on self-report surveys. Structural Equation Modeling, 13, 440–464. doi:10.1207/s15328007sem1303_6

DiStefano, C., & Motl, R. W. (2009). Personality correlates of method effects due to negatively worded items on the Rosenberg Self-Esteem scale. Personality and Individual Differences, 46, 309–313.

Eisenberg, E. M. (1984). Ambiguity as strategy in organizational communication. Communication Monographs, 51, 227–242.

Falcione, R. L. (1974). The factor structure of source credibility scales for immediate supervisors in an organizational contexts. Central States Speech Journal, 35, 63–66.

Finn, A. N., Schrodt, P., Witt, P., Elledge, N., Jernberg, K., & Larson, L. M. (2009). A meta-analytical review of teacher credibility and its associations with teacher behaviors and student outcomes. Communication Education, 58, 516–537. doi:10.1080/03634520903131154

French, J. R. P. Jr., & Raven, B. H. (1959). The bases of social power. In D. Cartwright (Ed.), Studies in social power (pp. 150–167). Ann Arbor, MI: University of Michigan Press.

Frymier, A. B., & Thompson, C. A. (1992). Perceived teacher affinity-seeking in relation to perceived teacher credibility. Communication Education, 41, 388–399.

Fusani, D. S. (1994). “Extra-class” communication: Frequency, immediacy, self-disclosure, and satisfaction in student-faculty interaction outside the classroom. Journal of Applied Communication Research, 22, 232–255.

Giffin, K. (1967). The contribution of studies of source credibility to as theory of interpersonal trust in the communication process. Psychological Bulletin, 68, 104–120.

Glascock, J., & Ruggiero, T. (2006). The relationship of ethnicity and sex to professor credibility at a culturally diverse university. Communication Education, 55, 197–207. doi:10.1080/03634520600566165

Haiman, F. S. (1949). An experimental study of the effects of ethos in public speaking. Speech Monographs, 16, 190–202.

Hargett, J. (1999). Students’ perceptions of male and female instructors’ level of immediacy and teacher credibility. Women and Language, 22, 46.

Heider, F. (1958). The psychology of interpersonal relations. New York: Wiley.

Hendrix, K. G. (1998). Student perceptions of the influence of race on professor credibility. Journal of Black Studies, 28, 738–763.

Hewgill, M. A., & Miller, G. R. (1965). Source credibility and response to fear-arousing communications. Speech Monographs, 32, 95–102.

Hofstede, G. (1983). National cultures in four dimensions: A research-based theory of cultural differences among nations. International Studies of Management and Organization, 13, 46– 75.

Hovland, C. I., Janis, I. I., & Kelley, H. H. (1953). Communication and persuasion. New Haven, CT: Yale University Press.

Hovland, C. I., & Weiss, W. (1952). The influence of source credibility on communication effectiveness. Public Opinion Quarterly, 15, 635–650.

Hurt, H. T., Scott, M. D., & McCroskey, J. C. (1978). Communication in the classroom. Reading, MA: Addison-Wesley.

Hutchens, J. S., & Hayes, T. (2014). In your Facebook: Examining Facebook usage as misbehavior on perceived teacher credibility. Education and Information Technology, 19, 5–20. doi:10.1007/s10639-012-9201-4

Infante, D. A. (1985). Inducing women to be more argumentative: Source credibility effects. Journal of Applied Communication Research, 13, 33–44.

Infante, D. A. (1987). Aggressiveness. In J. C. McCroskey & J. A. Daly (Eds.), Personality and interpersonal communication (pp. 157–192). Newbury Park, CA: Sage.

Infante, D. A., Meyers, S. A., & Buerkel, R. A. (1994). Argument and verbal aggression in constructive and destructive family and organizational disagreements. Western Journal of Communication, 58, 73–64.

Infante, D. A., & Rancer, A. S. (1996). Argumentativeness and verbal aggressiveness: A review of recent theory and research. In B. R. Burleson (Ed.), Communication yearbook 19 (pp. 319– 351). Thousand Oaks, CA: Sage.

Infante, D. A., & Wigley, C. J. III. (1986). Verbal aggressiveness: An interpersonal model and measure. Communication Monographs, 53, 61–69. doi:10.1080/03637758609376126

Isocrates (trans. 1929). Isocrates II (G. Norlin, Trans.). Cambridge, MA: Harvard University Press.

Jaasma, M. A., & Koper, R. J. (1999). The relationship of student-faculty out-of-class communication to instructor immediacy and trust and to student motivation. Communication Education, 48, 41–47.

Jaasma, M. A., & Koper, R. J. (2002). Out-of-class communication between female and male students and faculty: The relationship to student perceptions of instructor immediacy. Women’s Studies in Communication, 25, 119–137. doi:10.1080/07491409.2002.10162443

Johnson, K. A. (2011). The effects of Twitter® posts on students’ perceptions of instructor credibility. Learning, Media and Technology, 36, 21–38.

Kearney, P. (1984). Perceptual discrepancies in teacher communicator style. Communication, 13, 95–105.

Kearney, P., Plax, T. G., Hays, E. R., & Ivey, M. J. (1991). College teacher misbehaviors: What students don’t like about what teachers say and do. Communication Quarterly, 39, 309–324. doi:10.1080/0146337910936980

Kelley, H. H. (1967). Attribution theory in social psychology. In D. Levine (Ed.), Nebraska Symposium on Motivation (Vol. 15, pp. 192–238). Lincoln, NE: University of Nebraska Press.

Kelman, H. C., & Hovland, C. I. (1953). “Reinstatement” of the communicator in delayed measurement of opinion change. Journal of Abnormal and Social Psychology, 48, 327–335.

Kennedy, G. A. (1999). Classical rhetoric and its Christian and secular tradition from ancient to modern times. Chapel Hill, NC: University of North Carolina Press.

Kerssen-Griep, J., Trees, A. R., & Hess, J. A. (2008). Attentive facework during instructional feedback: Key to perceiving mentorship and an optimal learning environment. Communication Education, 57, 312–332.

Kerssen-Griep, J., & Witt, P. L. (2012). Instructional feedback II: How do instructor immediacy cues and facework tactics interact to predict student motivation and fairness perception? Communication Studies, 63, 498–217. doi:10.1080/10510974.2011.632660

Koermer, C. D., & Petelle, J. L. (1991). Expectancy violation and student rating of instruction. Communication Quarterly, 39, 341–350.

Knutson, T. J., & Posirisuk, S. (2006). Thai relational development and rhetorical sensitivity as potential contributors to intercultural communication effectiveness: JAI YEN YEN. Journal of Intercultural Communication Research, 35, 205–217.

Krathwohl, D. R., Bloom, B. S., & Masia, B. B. (1964). Taxonomy of educational objectives: The classification of educational goals. Handbook II − Affective domain. New York, NY: Holt, Rinehart, and Winston.

Kulp, D. H. (1934). Prestige as measured by single-experiences changes and their permanency. Journal of Educational Research, 27, 663–672.

Lannutti, P. J., Laliker, M., & Hale, J. L. (2001). Violations of expectations and social-sexual communication in student/professor interactions. Communication Education, 50, 69–82.

LePoire, B. A., & Burgoon, J. K. (1996). Usefulness of differentiating arousal responses within communication theories: Orienting response or defensive arousal within nonverbal theories of expectancy violation. Communication Monographs, 63, 208–230.

Martin, M. M., Chesebro, J. C., & Mottet, T. P. (1997). Students’ perceptions of instructors’ sociocommunicative style and the influence on instructor credibility and situational motivation. Communication Research Reports, 14, 431–440.

Martin, M. M., Weber, K., & Burant, P. A. (1997, April). Students’ perceptions of a teacher’s use of slang and verbal aggressiveness in a lecture: An experiment. Paper presented at the annual meeting of the Eastern Communication Association, Baltimore, MD.

Mazer, J. P., & Graham, E. E. (2015). Measurement in instructional communication research: A decade in review. Communication Education, 64, 208–240. doi:10.1080/03634523.2014.1002509

Mazer, J. P., Murphy, R. E., & Simonds, C. J. (2007). I’ll see you on ‘Facebook’: The effects of Computer-mediated teacher self-disclosure on student motivation, affective learning, and classroom climate. Communication Education, 56, 1–17. doi:10.1080/03634520601009710

Mazer, J. P., Murphy, R. E., & Simonds, C. J. (2009). The effects of teacher self-disclosure via “Facebook” on teacher credibility. Learning, Media, & Technology, 34, 175–183. doi:10.1080/17439880902923655

McComb, M. (1994). Benefits of computer‐mediated communication in college courses. Communication Education, 43, 159–170. doi:10.1080/03634529409378973

McCroskey, J. C. (1966). Scales for the measurement of ethos. Speech Monographs, 33, 65–72.

McCroskey, J. C. (1968). An Introduction to rhetorical communication. Englewood Cliffs, NJ: Prentice-Hall.

McCroskey, J. C. (1992). An introduction to communication in the classroom. Edina, MN: Burgess International Group.

McCroskey, J. C. (1998). An introduction to communication in the classroom (2nd ed.). Action, MA: Tapestry.

McCroskey, J. C. (2007). Source Credibility Measures. [Instrument with instructions]. Retrieved from http://www.jamescmccroskey.com/measures/source_credibility.htm

McCroskey, J. C., & Dunham, R. E. (1966). Ethos: A confounding element in communication research. Speech Monographs, 33, 456–463.

McCroskey, J. C., Holdridge, W., & Toomb, J. (1974). An instrument for measuring the source credibility of basic speech communication instructors. Speech Teacher, 23, 26–33.

McCroskey, J. C., & Jenson, T. A. (1975). Image of mass media news sources. Journal of Broadcasting, 19, 169–180.

McCroskey, J. C., & Richmond, V. P. (1983). Power in the classroom I: Teacher and student perceptions. Communication Education, 32, 175–184.

McCroskey, J. C., & Teven, J. J. (1999). Goodwill: A reexamination of the construct and its measurement. Communication Monographs, 66, 90–103. doi:10.1080/0363779909376464

McCroskey, J. C., Valencic, K. M., & Richmond, V. P. (2004). Toward a general model of instructional communication. Communication Quarterly, 53, 197–210. doi:10.1080/01463370409370192

McCroskey, J. C., & Young, T. J. (1981). Ethos and credibility: The construct and its measurement after three decades. Central States Speech Journal, 32, 24–34.

McPherson, M. B., Kearney, P., & Plax, T. G. (2003). The dark side of instruction: Teacher anger as classroom norm violations. Journal of Applied Communication Research, 31, 76–90.

McPherson, M. B., & Liang, Y. (2007). Students’ reactions to teachers’ management of compulsive communicators. Communication Education, 56, 18–33. doi:10.1080/03634520601016178

Mehrabian, A. (1969). Some referents and measures of nonverbal behavior. Behavioral Research Methods and Instrumentation, 1, 213–217.

Mehrabian, A. (1971). Silent messages. Belmont, CA: Wadsworth.

Miller, A. N., Katt, J. A., Brown, T., & Sivo, S. A. (2014). The relationship of instructor self-disclosure, nonverbal immediacy, and credibility to student incivility in the college classroom. Communication Education, 63, 1–16. doi:10.1080/03634523.2013.835054

Miller, G. R., & Hewgill, M. A. (1964). The effect of variations in nonfluency on audience ratings of source credibility. The Quarterly Journal of Speech, 50, 36–44.

Miller, G., & McReynolds, M. (1973). Male chauvinism and source competence: A research note. Speech Monographs, 40, 153–157.

Mottet, T. P., Parker-Raley, J., Beebe, S. A., & Cunningham, C. (2007). Instructors who resist “College Lite”: The neutralizing effect of instructor immediacy on students’ course-workload violations and perceptions of instructor credibility and affective learning. Communication Education, 56, 145–167. doi:10.1080/03634520601164259

Murphy, J. J. (1983). A synoptic history of classical rhetoric. Davis, CA: Hermagoras.

Myers, S. A. (1995). Student perceptions of teacher affinity-seeking and classroom climate. Communication Research Reports, 12, 192–199. doi:10.1080/08824099509362056

Myers, S. A. (2001). Perceived instructor credibility and verbal aggressiveness in the college classroom. Communication Research Reports, 18, 354–364.

Myers, S. A. (2004). The relationship between perceived instructor credibility and college student in-class and out-of-class communication. Communication Reports, 17, 129–137.

Myers, S. A., & Knox, R. L. (1999). Verbal aggression in the college classroom: Perceived use and student affective learning. Communication Quarterly, 47, 33–45.

Myers, S. A., & Martin, M. M. (2006). Understanding the source: Teacher credibility and aggressive communication traits. In T. P. Mottet, V. P. Richmond, & J. C. McCroskey (Eds.), Handbook of instructional communication: Rhetorical and relational perspectives (pp. 67– 88). Boston, MA: Pearson.

Neuliep, J. W. (2009). Intercultural communication: A contextual approach. Los Angeles, CA: Sage.

Nisbett, R. E. (2003). The geography of thought. How Asians and Westerners think differently and why. New York, NY: Free Press.

Norton, R. W. (1978). Foundation of a communicator style construct. Human Communication Research, 4, 99–112.

Nussbaum, J. F. (1992). Effective teacher behaviors. Communication Education, 41, 167–180.

Oetzel, J. G., & Ting-Toomey, S. (2003). Face concerns in interpersonal conflict: A cross-cultural empirical test of the face-negotiation theory. Communication Research, 30, 599–624. doi:10.1177/0093650203257841

O’Keefe, D. (2015). Persuasion: Theory and research (3rd ed.). Newbury Park, CA: Sage.

Osgood, C. E., Suci, G. J., & Tannenbaum, P. H. (1957). The measurement of meaning. Urbana, IL: University of Illinois Press.

Oyserman, D., Coon, H. M., & Kemmelmeier, M. (2002). Rethinking individualism and collectivism: Evaluation of theoretical assumptions and meta-analyses. Psychological Bulletin, 128, 3–72. doi:10.1037/0033-2909.128.1.3

Pogue, L., & AhYun, K. (2006). The effect of teacher nonverbal immediacy and credibility on student motivation and affective learning. Communication Education, 55, 331–344. doi:10.1080/03634520600748623

Powell, R. G., & Powell, D. L. (2010). Classroom communication and diversity (2nd ed.). London, England: Routledge.

Pytlak, M. A., & Houser, M. L. (2014). Because I’m the teacher and I said so: GTA use of behavior alteration techniques to establish power and credibility in the college classroom. Western Journal of Communication, 78, 287–309. doi:10.1080/10570314.2014.893010

Reinard, J. C. (2001). Introduction to communication research (3rd ed.). Boston, MA: McGraw-Hill.

Reinard, J. C. (2008). Introduction to communication research (4th ed.). Boston, MA: McGraw-Hill.

Richmond, V. P., & McCroskey, J. C. (1984). Power in the classroom II: Power and learning. Communication Education, 33, 125–136.

Richmond, V. P., & McCroskey, J. C. (1990). Reliability and separation of factors on the assertiveness-responsiveness measure. Psychological Reports, 67, 449–450.

Richmond, V. P., & Roach, K. D. (1992). Power in the classroom: Seminal studies. In V. P. Richmond & J. C. McCroskey (Eds.), Power in the classroom: Communication, control, and concern (pp. 47–65). Hillsdale, NJ: Lawrence Erlbaum Associates.

Rubin, D. L. (1998). Help! My professor (or doctor or boss) doesn’t talk English. In J. N. Martin, T. K. Nakayama, & L. A. Flores (Eds.), Readings in cultural contexts (pp. 149–160). Mountain View, CA: Mayfield Publishing Company.

Rubin, R. B., & Feezel, J. D. (1986). A needs assessment of research in communication education. Central States Speech Journal, 37, 113–118.

Russ, T. L., Simonds, C. J., & Hunt, S. K. (2002). Coming out in the classroom … An occupational hazard?: The influence of sexual orientation on teacher credibility and perceived student learning. Communication Education, 51, 311–324. doi:10.1080/03634520216516

Sabee, C. M., & Wilson, S. R. (2005). Students’ primary goals, attributions and facework during conversations about disappointing grades. Communication Education, 54, 185–204. doi:10.1080/03634520500356154

Sallinen-Kuparinen, A. (1992). Teacher communicator style. Communication Education, 41, 153– 166.

Santilli, V., Miller, A. N., & Katt, J. (2011). Comparison of the relationship between instructor nonverbal immediacy and teacher credibility in Brazilian and U.S. classrooms. Communication Research Reports, 28, 266–274. doi:10.1080/08824096.2011.588583

Schrodt, P., & Turman, P. D. (2005). The impact of instructional technology use, course design, and sex differences on students’ initial perceptions of instructor credibility. Communication Quarterly, 53, 177–196.

Schrodt, P., & Witt, P. L. (2006). Students’ attributions of instructor credibility as a function of students’ expectations of instructional technology use and nonverbal immediacy. Communication Education, 55, 1–20. doi:10.1080/03634520500343335

Schutt, M., Allen, B. S., & Laumakis, M. A. (2009). The effects of instructor immediacy behaviors in online learning environments. Quarterly Review of Distance Education, 10, 135–148.

Self, C. C. (1996). Credibility. In M. B. Salwen & D. W. Stacks (Eds.), An integrated approach in communication theory and research (pp. 421–441). Mahwah, NJ: Lawrence Erlbaum.

Semlak, J. L., & Pearson, J. C. (2008). Through the years: An examination of instructor age and misbehavior on perceived teacher credibility. Communication Research Reports, 25, 76–85. doi:10.1080/08824090701831867

Sidelinger, R. J., & McCroskey, J. C. (1997). Communication correlates of teacher clarity in the classroom. Communication Research Reports, 14, 1–10.

Smith, C. R. (2012). Rhetoric and human consciousness: A history (4th ed.). Prospect Heights, IL: Waveland.

Stiff, J. B. (1986). Cognitive processing of persuasive message cues: A meta-analytic review of the effects of supporting information on attitudes. Communication Monographs, 53, 75–89.

Stiff, J. B., Dillard, J. P., Somera, L., Kim, H., & Sleight, C. (1988). Empathy, communication, and prosocial behavior. Communication Monographs, 55, 198–213.

Teven, J. J. (2001). The relationships among teacher characteristics and perceived caring. Communication Education, 50, 159–169.

Teven, J. J. (2007). Teacher caring and classroom behavior: Relationships with student affect, teacher evaluation, teacher competence, and trustworthiness. Communication Quarterly, 55, 433–450. doi:10.1080/01463370701658077

Teven, J. J., & Comadena, M. E. (1996). The effects of office aesthetic quality on students’ perceptions of teacher credibility and communicator style. Communication Research Reports, 13, 101–108.

Teven, J. J., & Gorham, J. (1998). A qualitative analysis of low inference student perceptions of teacher caring and on-caring behaviors within the college classroom. Communication Research Reports, 15, 288–298.

Teven, J. J., & Hanson, T. L. (2004). The impact of teacher immediacy and perceived caring on teacher competence and trustworthiness. Communication Quarterly, 52, 39–53. doi:10.1080/01463370409377

Teven, J. J., & Herring, J. E. (2005). Teacher influence in the classroom: A preliminary investigation of instructor power, perceived credibility, and student satisfaction. Communication Research Reports, 22, 235–246. doi:10.1080/00036810500230685

Teven, J. J., Martin, M. M., & Neupauer, N. (1998). Sibling relationships: Verbally aggressive messages and their effect on relational satisfaction. Communication Reports, 11, 179–186.

Teven, J. J., & McCroskey, J. C. (1997). The relationship of perceived teacher caring with student learning and teacher evaluation. Communication Education, 46, 1–9.

Thomas, C. E. (1995, November). A theoretical model of the relationship between teacher personality variables, classroom communication behaviors, and student outcomes. Paper presented at the annual convention of the Speech Communication Association, San Antonio, TX.

Thomas, C. E., Richmond, V. P., & McCroskey, J. C. (1994). The association between immediacy and socio-communicative style. Communication Research Reports, 11, 107–115. doi:10.1080/08824099409359946

Thweatt, K. S., & McCroskey, J. C. (1998). The impact of teacher immediacy and misbehaviors on teacher credibility. Communication Education, 47, 348–358.

Trad, L., Katt, J., & Miller, A. N. (2014). The effect of face threat mitigation on instructor credibility and student motivation in the absence of instructor nonverbal immediacy. Communication Education, 63, 136–148. doi:10.1080/03634523.2014.889319

Trees, A. R., Kerssen-Griep, J., & Hess, J. A. (2009). Earning influence by communicating respect: Facework’s contributions to effective instructional feedback. Communication Education, 58, 397–416. doi:10.1080/03634520802613419

Triandis, H.C. (1995). Individualism and collectivism. Boulder, CO: Westview Press.

Tuppen, C. J. S. (1974). Dimensions of communicator credibility: An oblique solution. Speech Monographs, 41, 253–260.

Venable, K. V., & Martin, M. M. (1997). Argumentativeness and verbal aggressiveness in dating relationships. Journal of Social Behavior and Personality, 12, 955–964.

Whitehead, J. L. (1968). The measurement of ethos (Unpublished doctoral dissertation). Northwestern University, Chicago, IL.

Witt, P. L., & Kerssen-Griep, J. (2011). Instructional feedback I: The interaction of facework and immediacy on students’ perceptions of instructor credibility. Communication Education, 60, 75–94. doi:10.1080/03634523.2010.507820

Witt, P. L., & Wheeless, L. R. (1999). Nonverbal communication expectancies about teachers and enrollment behavior in distance learning. Communication Education, 48, 149–154. doi:10.1080/03634529909379162

Wooten, A. G., & McCroskey, J. C. (1996). Student trust of teacher as a function of sociocommunicative style of teacher and socio-communicative orientation of student. Communication Research Reports, 13, 94–100.

Wrench, J. S., & Punyanunt, N. M. (2004). Advisee-advisor communication: An exploratory study examining interpersonal communication variables in the graduate advisee-advisor relationship. Communication Quarterly, 52, 224–236.

Wrench, J. S., Thomas-Maddox, C., Richmond, V. P., & McCroskey, J. C. (2013). Quantitative research methods: A hands-on approach (2nd ed.). New York, NY: Oxford University Press.

Zhang, Q. (2009). Perceived teacher credibility: A multi-cultural test of a credibility-learning model. Western Journal of Communication, 73, 326–347. doi:10.1080/10570310903082073