Introducing the Tableau interface
Connecting to the data
Open Tableau Public or Tableau Desktop and select Text file from the Connect menu. On the next screen click Update Now to preview the data. If it imports correctly click Sheet1 near the bottom of the screen to create a graph or table.
The Tableau Sheet
Like Excel, Tableau can have multiple Sheets represented by tabs at the bottom of the screen. Each sheet is a space to create a graph. Here’s a new sheet with the sample dataset.
- dataset variables are listed on the left
- variables can be dragged onto the Rows and Columns shelves to add them to the display
- use the Show me button to select a graph type
- adjust color, size, and labels using the Marks cards
Dimensions and measures
During data import Tableau guesses whether each variable in the dataset represents a Dimension or a Measure.
- Dimension. A categorical or ordinal variable, often used to subdivide or filter the data (e.g. Labour Force Status or Province). Dimensions appear at the top of the variable list, above the horizontal line.
- Measure. An interval or ratio variable, often used in calculations (e.g. Statistical weight or Usual Hourly Wages). Measures are at the bottom of the variable list, below the horizontal line.
Categorical variables whose values are numerical codes are sometimes misinterpreted by Tableau. In this dataset Sex is a categorical variable with values of either “1” (Male) or “2” (Female). It should be a Dimension but Tableau interprets it as a Measure because the categories are encoded as numbers (1 or 2). To fix this you may drag the Sex variable from its current position below the horizontal line and drop it above the line with the other Dimensions. (Another method is to right-click the Sex variable and choose Convert to Dimension.)
It is important for variables to be identified correctly, as Dimensions and Measures have different properties and are handled differently by the software.
Tableau interface tips
A good way to get used to the Tableau interface is to experiment and see what happens. Here are some tips as you get started.
- Right-click menus. Many options are available by right-clicking in the Tableau interface. Explore the right-click menus for dimensions and measures (you can also right-click graph elements to hide, group, filter, and format them).
- Undo. If you take a wrong turn you can always undo your actions using the back arrow in the menu bar (above the sheet) or Ctrl+Z (Cmd+Z on a Mac)
- Show Me. The Show Me button in the top right corner suggests graph types that may work with the dimensions and measures you have added to the sheet.
- Duplicate. Right-click your sheet tab (bottom of the screen) and select Duplicate to create a copy that you can play with while preserving the first one. This can be useful as you build graphs, allowing you to experiment but return quickly to an earlier version if things don’t turn out.