At the most fundamental level, a visualization in Tableau is created by placing one or more fields on one or more shelves. As an example, note that the visualization created in the following diagram is generated by placing the Sales field on the Text shelf:

Exercise: fundamentals of visualizations

Let's explore the basics of creating a visualization using an exercise:

1. Navigate to https://public.tableau.com/profile/marleen.meier to locate and download the workbook associated with this chapter.

2. In the workbook, find the tab labeled Fundamentals of Visualizations:

 

3. Locate Department within the Dimensions portion of the Data pane:

4. Drag Department to the Color shelf:

5. Click on the Color shelf and then on Edit Colors to adjust the colors as desired:

6. Move Department to the Size, Label/Text, Detail, Columns, and Rows shelves. After placing Department on each shelf, click on the shelf itself to access additional options.

7. Drop other fields on various shelves to continue exploring Tableau's behavior.

As you explore Tableau's behavior by dragging and dropping different fields onto different shelves, you'll notice that Tableau responds with default behaviors. These defaults, however, can be overridden, which we'll explore next.

Beyond the default behavior

In the preceding exercise, Fundamentals of visualizations, we can notice that the Marks card reads Automatic. This means that Tableau is providing the default view. The default view can be easily overridden by choosing a different selection from the drop-down menu:

Another type of default behavior can be observed when dragging a field onto a shelf. For example, dragging and dropping a measure onto a shelf will typically result in the SUM () aggregation.

Note

In Windows, you can override this default behavior by right-clicking and dragging a field from the Data pane and dropping it onto a shelf. Tableau will respond with a dialog box with possible options.

Here's a screenshot of the popup that will appear:

Exercise: overriding defaults

Let's walk through an exercise where we'll override the two default behaviors shown in the preceding screenshot:

1. In the workbook associated with this chapter, navigate to the Overriding Defaults worksheet.
2. Right-click and drag Date of Hire to the Columns shelf.

 

3. In the resulting dialog box, choose the second instance of MONTH (Date of Hire):

4. Place Number of Records on the Rows shelf and Department on the Detail shelf.

 

5. Click on the dropdown in the Marks card and select Area:

Show Me

Show Me allows the Tableau author to create visualizations at the click of a button. To understand how it works, let's refer to the following screenshot:

 

Now let's look at the following aspects that are highlighted in the preceding screenshot:

• A: Selected fields in theDatapane.
• B: Fields deployed in the view, that is, pills.
• C: The recommended view.
• D: Help text that communicates the requirements for creating the recommended view or any selection choice over which the cursor is placed.

Every icon in Show Me that isn't greyed out represents a visualization that can be created simply by clicking on it. For example, in the diagram preceding, the Tableau author may choose to click on the pie chart icon to create a pie chart based on the selected and deployed fields.

Note

Show Me options are highlighted based on two criteria: the selected fields in the Data pane and the fields deployed in the view.

Show Me may be effectively used for the following reasons:

• Efficiency: The proficient Tableau author already knows how to create the basic visualization types.Show Meautomates these basic types and thus may be used for quicker production.
• Inspiration: Determining an effective way to visualize a dataset can be challenging.Show Mecan help with this challenge by allowing the Tableau author to quickly consider various options.
• Education: An inexperienced Tableau author may accessShow Meto better understand how various visualizations are created. By reading the help text displayed at the bottom ofShow Meand observing the results generated by clicking on various options, much can be learned.

These three reasons demonstrate the strong capabilities that Show Me provides for worksheet creation, however, be careful not to use it as a crutch. If you click on the various options without understanding how each visualization is created, you're not only shortchanging the educational process, but you may generate results that aren't well-understood, and could thus lead to detrimental business decisions.

Although, as stated in the Creating worksheets and dashboards section, a Dashboard contains one or more worksheets, and Dashboards are much more than static presentations. They're an essential part of Tableau's interactivity. In this section, we'll populate a Dashboard with worksheets and then deploy actions for interactivity.

Exercise: building a dashboard

The following are the steps for building a Dashboard:

1. In the Chapter 1 workbook, navigate to the Building a Dashboard tab.

 

2. In theDashboard pane, located on the left side of the screen, double-click on each of the following worksheets (in the order in which they are listed) to add them to the Dashboard pane: Age/State, Pay Rate, Tree Map, Date of Hire, and Date of Termination:

 

3. In the bottom-right corner of the Dashboard pane, click in the blank area to select a container. After clicking in the blank area, you should see a blue border around the filter and the legends. This indicates that the vertical container is selected:

 

4. Select the vertical container handle and drag it to the left side of the Customers worksheet. Note the grey shading, which communicates where the container will be placed:

Note

The grey shading provided by Tableau when dragging elements, such as worksheets and containers, onto a Dashboard, helpfully communicates where the element will be placed. Take your time and observe carefully when placing an element on a Dashboard or the results may be unexpected.

5. Format the dashboard as desired. The following tips may prove helpful:
   • Adjust the sizes of the elements on the screen by hovering over the edges between each element and then clicking and dragging as desired.
   • Note that the Age legend and Department filter in the following screenshot are floating elements. Make an element floating by right-clicking on the element handle and selecting Floating (see the previous screenshot and note that the handle is located immediately above the word Region in the top-right corner).
   • Create horizontal and vertical containers by dragging those objects from the bottom portion of the Dashboardpane.
   • Drag the edges of containers to adjust the size of each worksheet.
   • Display theDashboardtitle through the Dashboard, right-click Show Title:

Exercise: adding interactivity to a dashboard

One of the primary benefits of Tableau is the interactivity it provides the end user. Dashboards aren't simply for viewing; they're meant for interaction. In this exercise, we'll add interactivity to the Dashboard that was created in the previous exercise:

1. Starting where the previous exercise ended, click the drop-down menu associated with the Department filter and select Apply to Worksheets, and then All Using This Data Source:

2. To use the map as a filter for the other worksheets on the Dashboard pane, click the Use as Filter icon located at the top-right corner of the Age/State worksheet:

3. Set Pay Rate to Use as Filter.
4. Navigate to Dashboard > Actions.

 

5. In the dialog box, click Add Action > Filter and create a filter, as shown:

Having completed the preceding dashboard exercise, you should now be able to click on various objects on the dashboard to observe the interactivity. To learn advanced dashboard techniques, be sure to check out Chapter 11, Visualization Best Practices and Dashboard Design.

Let's compare the instance of the Superstore data source with a new connection to the same data:

The following are the steps for connecting to Tableau Server:

Having completed the preceding two exercises, let's discuss the most germane point, that is, metadata. Metadata is often defined as data about the data. In the preceding case, the data source name, default aggregation, default number formatting, and hierarchy are all examples of Tableau remembering changes made to the metadata. This is important because publishing a data connection allows for consistency across multiple Tableau authors. For example, if your company has a policy regarding the use of decimal points when displaying currency, that policy will be easily adhered to if all Tableau authors start building workbooks by pointing to data sources where all formatting has been predefined.

 

In step 7 of this exercise, the fact that the Profit Ratio calculated field wasn't directly editable when accessed by connecting to Tableau Server as a data source has important implications. Imagine the problems that would ensue if different Tableau authors defined Profit Ratio differently. End users would have no way of understanding what Profit Ratio really means. However, by creating a workbook based on a published data source, the issue is alleviated. One version of Profit Ratio is defined and it can only be altered by changing the data source. This functionality can greatly assist consistency across the enterprise.

Let's explore the following steps for creating a local data connection using an example:

The following are the steps for the exercise:

Perhaps the interrelationship between Measure Names and Measure Values is best explained by an analogy. Consider several pairs of socks and a partitioned sock drawer. Step 2 is the equivalent of throwing the socks into a pile. The results are well, disorganized. Step 4 is the equivalent of an empty sock drawer with partitions. The partitions are all in place but where are the socks? Step 5 is a partitioned drawer full of nicely-organized socks. Measure Names is like the partitioned sock drawer. Measure Values is like the socks. Independent of one another, they aren't of much use. Used together, they can be applied in many different ways.

Tableau provides various shortcuts to quickly create a desired visualization. If you're new to the software, this shortcut behavior may not seem intuitive. But with a little practice and a few pointers, you'll quickly gain an understanding of it. Let's use the following exercise to explore how you can use a shortcut to rapidly deploy Measure Names and Measure Values:

 

 

Exercise: commentary

Several things happened in step 2 of the Measure Names and Measure Values shortcuts exercise. After placing Age on top of the Pay Rate number in the view, Tableau did the following:

1. Deployed Measure Names on the Filters shelf.
   • Open the Measure Names filter and observe that only Age and Pay Rate are selected. This limits the view to display only those two measures.

2. Deployed Measure Names on the Rows shelf.
   • Measure Names is acting like a partitioned container, that is, like the sock drawer in the analogy. Because of the filter, the only rows that display are for Age and Pay Rate.

3. Displayed the Measure Values shelf.
   • The Measure Valuesshelf is somewhat redundant. Although it clearly shows the measures that display in the view, it essentially acts as an easy way to access the filter. You can simply drag measures on and off of theMeasure Valuesshelf to adjust the filter and thus display/hide additional Measure Values. You can also change the order within theMeasure Valuesshelf to change the order of the measures in the view.

4. Deployed Measure Values on the Text shelf.
   • Measure Values is simply defining the numbers that will display for each row; in this case, the numbers associated with Age and Pay Rate.

If the visualization has an axis, the shortcut to deploy Measure Names and Measure Values requires the placement of a second measure on top of the axis of an initial measure, as follows:

 

Tableau categorizes every field from an underlying data source as either a dimension or a measure. A dimension is qualitative or, to use another word, categorical. A measure is quantitative or aggregable. A measure is usually a number but may be an aggregated, non-numeric field, such as MAX (Date of Hire). A dimension is usually a text, Boolean, or date field, but may also be a number, such as Pay Rate. Dimensions provide meaning to numbers by slicing those numbers into separate parts/categories. Measures without dimensions are mostly meaningless.

Exercise: dimensions and measures

Let's look at an example to better understand:

1. In the workbook associated with this chapter, navigate to the Dimensions and Measures worksheet.
2. Drag Number of Records to the Rows shelf.

 

3. Place Date of Hire and Department on the Columns shelf:

The result of step 2 is mostly meaningless. The Number of Records measure is about 302, but without the context supplied by slicing the measure with one or more dimensions, there is really no way to understand what it means. Step 2 brings meaning. Placing Date of Hire and Department on the Columns shelf provides context, which imparts meaning to the visualization.

There are three levels of calculations in Tableau: Row, Aggregate, and Table. To understand how these three levels function, it's important to know the Tableau process flow.

 

We can see the process flow in the following diagram:

Let's follow the flow to understand where the three levels of calculations take place. We'll do so with an example that considers the Number of Records and Quantity fields. Assuming we're using SQL, consider the following calculation types, calculated fields, and queries. Note that the SQL is slightly simplified for the sake of this example.

Let's take a deeper look at the three levels of calculations and consider the example in the following table:

 

For the Row- and Aggregate-level calculations, the computation is actually completed by the data source engine. Tableau merely displays the results. This, however, isn't the case for the Table-level calculation. Although the query passed to the data source for the Table-level calculation is identical to the query for the Aggregate-level calculation, Tableau performs additional computations on the returned results. Let's explore this further with an exercise using the same calculated fields.

 

Exercise: row level, aggregate level, table level

Let us look at the following steps and begin our exercise:

1. In the workbook associated with this chapter, navigate to the Row_Agg_Tbl worksheet.
2. Select Analysis > Create Calculated Field to create the following calculated fields. Note that each must be created separately, that is, it isn't possible in this context to create a single calculated field that contains all three calculations:

Name	Calculation
Lev – Row	[Number of Records]/[Quantity]
Lev – Agg	SUM ([Number of Records])/SUM (Quantity)
Lev – Tab	WINDOW_AVG ([Lev - Agg])

 

3. In the Data pane, right-click on the three calculated fields you just created and select Default Properties | Number format.
4. In the resulting dialog box, select Percentage and click OK.
5. Place Order Date on the Columns shelf.
6. Place Measure Names on the Rows shelf, and Measure Values on the Text shelf.
7. Exclude all values except for Lev - Row, Lev - Agg, and Lev - Tab:

 

Exercise: commentary

Lev - Agg is an aggregate-level calculation. The computation is completed by the data source engine. The sum of [Number of Records] is divided by the sum of [Quantity]. The results of the calculation are likely useful for the Tableau author.

Lev - Row is a row-level calculation. The computation is completed by the data source engine. [Number of Records] is divided by [Quantity] for each row of the underlying data. The results are then summed across all rows. Of course, in this case, the row-level calculation doesn't provide useful results; however, since a new Tableau author may mistakenly create a row-level calculation when an aggregate-level calculation is what's really needed, the example is included here.

Lev - Tab is a table calculation. Some of the computation is completed by the data source engine, that is, the aggregation. Tableau completes additional computation on the results returned from the data source engine. Specifically, the results of Lev - Agg are summed and then divided by the number of members in the dimension. For the preceding example, this is (26.29% + 26.34% + 26.30% + 26.55%)/4. Once again, the results in this case aren't particularly helpful but do demonstrate knowledge the budding Tableau author should possess.

Continuous and discrete aren't concepts that are unique to Tableau. Indeed, both can be observed in many arenas. Consider the following example:

The preceding diagram is of two rivers: River-Left and River-Right. Water is flowing in River-Left. River-Right is composed of ice cubes. Could you theoretically sort the ice cubes in River-Right? Yes! Is there any way to sort the water in River-Left? In other words, could you take buckets of water from the bottom of the river, cart those buckets upstream and pour the water back into River-Left and thereby say, I have sorted the water in the river? No. The H₂O in River-Left is in a continuous form, that is, water. The H₂O in River-Right is in a discrete form, that is, ice.

 

 

Having considered continuous and discrete examples in nature, let's turn our attention back to Tableau. Continuous and discrete in Tableau can be more clearly understood with the following seven considerations:

 

 

While developing a Dashboard, the Tableau Creator has the option to take a look at Device Designer or Device Preview. You can find it here: 

Please be aware that you can only use the sheets that are in the default layout of your Dashboard. Once you're in the Device Designer mode, select a Device type and you'll get choices of the most common Models:

 

 

 

 

 

 

A cellphone is usually designed in portrait orientation. Now move the content in a way that the sheets you want to see on your phone are within the device frame. Satisfied? Then add this layout (top-right corner) to the workbook. It will appear under the Default one on the top-left side:

The user can now select the design needed, whenever opening a Workbook from the Tableau Server.

A Tablet Dashboard works exactly the same as the cellphone one. Follow the preceding steps to create it, except you have to choose the Tablet Device Type of course and a Tablet's Dashboard is usually in Landscape orientation.