3.2 Building Visualization Types & Show Me

3.2 Building Visualization Types & Show Me

Tableau Desktop provides a vast array of chart types to present data effectively. On the Tableau Desktop Specialist exam, candidates are tested on chart creation mechanics, field placement requirements, the behavior of the Show Me panel, geographic roles, and dual-axis chart construction.

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The Show Me Panel

The Show Me panel (located in the upper-right corner of the workspace) acts as an intelligent visual builder. It displays 24 core visualization thumbnail icons.

• Field Requirements: When you hover over any chart icon in Show Me, the panel displays the exact minimum field combination required to build that visualization (e.g., "For text tables, try 1 or more Dimensions and 1 or more Measures").
• Active vs. Grayed-out Icons: Chart icons are active (colored) if the currently selected fields in the Data Pane or view satisfy the visual requirements. Icons are grayed-out if the minimum field criteria are not met.
• Automatic Field Assignment: Clicking a chart type in Show Me automatically places the selected fields onto the appropriate shelves (Rows, Columns, Marks, Color, Size, Detail) to generate the chart.

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Core Visualization Types and Construction Rules

1. Tables and Cross-Tabs

• Text Tables (Cross-tabs): Requires 1+ Dimensions and 1+ Measures. Displays numerical data in rows and columns of text cells.
• Heat Maps: Requires 1+ Dimensions and 1-2 Measures. Uses mark size and color intensity (rectangles) to compare values across dimensions.
• Highlight Tables: Requires 1+ Dimensions and 1 Measure. Adds a background color fill to text table cells based on measure values, making extreme high/low values stand out immediately.

2. Bar Charts

• Horizontal Bar Charts: Requires 0+ Dimensions and 1+ Measures. Default mark type when a measure is placed on Columns and a dimension on Rows.
• Stacked Bar Charts: Requires 1+ Dimensions, 1+ Measures. Created when a second dimension is added to the Color card on a bar chart.
• Side-by-Side Bar Charts: Requires 1+ Dimensions, 1+ Measures. Displays bars side-by-side for category comparisons across sub-categories.

3. Time-Series Charts (Line & Area Charts)

• Line Charts: Requires 1 Date, 0+ Dimensions, 1+ Measures.
  • Discrete Date Line: Placing a discrete blue date field (e.g., YEAR([Order Date])) on Columns breaks the line chart into separate panes or headers per year.
  • Continuous Date Line: Placing a continuous green date field (e.g., continuous [Order Date]) on Columns generates a single, continuous, uninterrupted timeline axis.
• Area Charts: Requires 1 Date, 0+ Dimensions, 1+ Measures. Shades the region below line charts to emphasize total volume over time.

4. Geographic Maps

Tableau automatically assigns Geographic Roles (such as Country, State, City, Zip Code, Airport) to fields containing geographic names or codes, indicated by a globe icon (🌐) in the Data Pane.

• Automatic Lat/Long: When a geographic field is placed in a view, Tableau automatically generates Latitude (generated) and Longitude (generated) continuous measure pills on Rows and Columns.
• Symbol Maps: Requires 1 geographic dimension and 0-2 measures. Plots discrete mark circles at specific latitude/longitude points. Circle size and color can encode measures.
• Filled Maps (Choropleth): Requires 1 geographic dimension and 0-1 measure. Colors entire polygon boundaries (e.g., state or country borders) based on measure values.

5. Distribution Charts

• Histograms: Requires 1 Continuous Measure.
  • Mechanics: Clicking Histogram in Show Me automatically creates a new Binned Dimension from the measure (e.g., [Profit (bins)]) and places CNT(Data Source) or record count on Rows.
  • Purpose: Displays the frequency distribution of continuous numerical data in equal-sized bin containers.
• Box Plots (Box-and-Whisker Plots): Requires 0+ Dimensions and 1+ Measures.
  • Purpose: Displays distribution statistical summaries including Median (50th percentile), Interquartile Range (IQR between 25th and 75th percentiles), Whiskers (1.5x IQR), and outlier data points.

6. Relational & Part-to-Whole Charts

• Scatter Plots: Requires 0+ Dimensions and 2 Continuous Measures (one on Columns, one on Rows). Evaluates relationship, correlation, or clustering between two quantitative variables.
• Treemaps: Requires 1+ Dimensions and 1-2 Measures. Uses nested rectangles where rectangle area represents one measure (e.g., Sales) and color represents another measure (e.g., Profit).
• Bullet Graphs: Requires 1+ Dimensions and 2 Measures. Used to evaluate performance against a target goal (e.g., Actual Sales vs. Target Sales), featuring a main bar and reference target line.
• Pie Charts: Requires 1+ Dimensions and 1-2 Measures. Encodes part-to-whole relationships using angle/slice size. Best Practice: Limit pie charts to 5 or fewer slices for legibility.

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Dual-Axis & Combination Charts

A Dual-Axis Chart overlays two independent measures in the same visualization window, creating two separate axes (one on the left, one on the right).

[Rows Shelf]: SUM([Sales])  |  SUM([Profit])  (Right-click -> Dual Axis)

Step-by-Step Dual-Axis Creation

1. Place a dimension (e.g., [Order Date]) on Columns.
2. Place two measures (e.g., SUM([Sales]) and SUM([Profit])) side-by-side on Rows.
3. Right-click the second measure pill on Rows (SUM([Profit])) and select Dual Axis.
4. CRITICAL EXAM STEP - Synchronize Axis: By default, Tableau scales the left and right axes independently based on each measure's numeric range. To ensure an accurate visual comparison, right-click the right-hand axis and select Synchronize Axis.
5. Marks Card Customization: Once Dual Axis is enabled, the Marks card splits into three sections: All, [Measure 1], and [Measure 2]. You can change the Mark Type independently for each measure—for example, setting Sales to Bar and Profit to Line to create a Combination Chart.

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Show Me Field Requirements Summary Matrix