Another Tableau invention is the use of cards. Cards are containers for various controllers: which are dialogs in the Tableau workspace that allow various data elements and components to be configured. The most important card is the Marks card, which is in the most current version of Tableau Public. It has combined various controllers into one.
The Marks card is a compact yet highly functional area of the worksheet view that contains different controllers for data element chart properties (these data points on a chart are called marks). To use the Marks card, drag and drop data elements onto a corresponding shelf (such as Colors, Label, and Size). This will change the chart visualization by changing the chart mark properties.
The different controllers on the Marks card, which are commonly referred to as shelves, include the following:
- Colors: This changes the colors of marks in the chart (such as bar or line colors). In our example, the Set that shows whether an airline is in the top five worst airlines according to their average delay time is on the Color shelf.
- Size: This configures the sizes of data points or elements in charts.
- Label/Text: This adds a label to the chart for data points, bars, groupings, or lines. In our example, the percentage difference in average delay time between the top five worst airlines and all the others is on the Label shelf.
- Details: This adds details to the chart or data points, allowing you to keep the main structure of the chart. However, it further categorizes it in detail and with more granularity. For example, if we add Unique Carrier to the Detail shelf, our visualization will aggregate the average departure time by day for each Unique carrier, which means that there is now a bar segment for each carrier, and the story that our graph tells will change dramatically, as shown in the following screenshot:
- Tool Tip: This allows you to add context and calls to action, which are critical for telling stories because they instruct users how to progress to the next step and they better illustrate how a data point relates to a user's interests.
- Shape: This sets the data point shape in the chart visualization.
- Path: This is typically used for routes on a map. This controller allows a path to be sequentially built and placed on a map visualization. This is commonly seen in tornado and hurricane tracking maps visualizations.
Once a field is on a shelf on the Marks card, it shows up under the shelves with a small icon for the shelf type followed by the field name, as shown in the following screenshot:
You can change the shelf on which a field is placed by clicking on the small icon and then selecting the shelf to which you'd like to move the field, as shown in the previous screenshot.
The Filters shelf is where you drag fields to limit the data points that your users see in your visualization. When you drag it to the Filters shelf, Tableau Public will prompt you to filter a field according to its type.
You can also filter a visualization based on the inclusion in a Data set. If you want to show the filters to users, you can right-click on the fields in the data window to Show Quick Filters as well. We will describe filtering in depth in future chapters.
In the following screenshot, we have added WEEK(Flight Date) to the Pages shelf. The controller appears here. We can set the speed at which the visualization changes. In the Tableau Public desktop client, the visualization will progress sequentially once you click on the Play button. However, online, it will not progress automatically. Your user will need to click on the Play button to proceed.
Since the functionality is limited online and that is where your users will interact with your work, we will condense the discussion of the Page shelf:
The tabs at the bottom of the Tableau Public screen are either sheet or dashboard tabs. The tabs with a series of rows and a column on them are sheet tabs, where you can design objects that fit on one sheet. The tabs with a rectangle divided into four quadrants are dashboard tabs, where you can add one or more sheets in order to form a unified dashboard. When you click on one of the new (blank) worksheet or dashboard tabs, that tab opens and names the sheet or dashboard the next sequential name, such as Sheet 3 or Dashboard 2. The sheet or dashboard is blank when you first open a new tab.
Tip
A dashboard is really just a group of worksheets on the same page. You can assemble a dashboard after creating the various component worksheets that it will contain. Dashboards are assembled and configured by using the Dashboard tabs in Tableau Public, which are available in the lower row of the tabs in the Tableau Public interface.
The lower-right hand side of the Tableau Public interface also contains three workspace control tabs, as shown in the following screenshot:
Let's take a look at each of these tabs:
- Show Sheet Sorter: This shows the sheets in your workbook and allows you to reorder them easily
- Show Filmstrip: This shows the visualization with the thumbnails of other worksheets, which is shown in the previous screenshot
- Show Tabs: This shows the default view of the visualization and the named tabs of other worksheets, as shown in the previous screenshot