1: Back in the middle 20th century, reliability and validity were discussed as a property of the scale (i.e., the Osborne Obsequiousness Scale is reliable and valid). Modern APA and other guidelines recommend that we talk about reliability and validity as the property of samples, not instruments. However, some instruments do tend to appear more reliable across samples, and some less so. Hence the need for replication. [return]

2: Although neither practice seems to have been adopted widely in the literature, we are familiar with. [return]

3: This implies that there is a distribution of split-half coefficients based on different splits, and that alpha is the mean of all these splits. This is an interesting idea that many of us miss, as we focus just on the one number we calculate. [return]

4: Most people would agree this statement is “self-evident”—a nice way of saying “well, duh!” but it is surprising that this simple “well, duh!” sentiment is so problematic in practice. [return]

5: We know that this sample of N=656 is relatively small to consider its results close to our “population” estimates, but we will do so anyhow for the purpose of this example. [return]

6: Note: The characters &ss represent the value of the input parameter for the macro. Thus, when we are using N=50, our output data set will be orig_alpha50. This is true for the remaining examples. [return]