The marks card located on the bottom shelf is one of the most commonly used tools in Tableau. Marks card gives the visualization detail and context. Using marks card we can easily reduce a large volume of data to a simple, comprehensible visualization.
As we drag and drop fields from the Data pane, we add context and detail to the fields by using the various elements in the marks card.
The clever aspect of Tableau is that it automatically detects the mark type for our view.
Let’s look at some cases where Tableau decides a mark type.
Text – When you drag and drop two dimensions on the Row and Column shelves.
Shape – When you drag and drop two measures on the Row and Column shelves.
Bar – When you drag and drop a dimension and a measure on the Row and Column shelves.
Line – When you drag and drop a date and a measure on the Row and Column shelves.
Watch our video tutorial on marks card on this link.
Now let us look at each of these marks individually.
Text mark – When you want data to be represented just as numbers or in the form of a table.
Bar Mark – Used for categorical comparisons.
Line mark – Used to depict trends over a period of time.
Area mark – Used for relative comparisons using the size over a period of time.
Square mark – Used when you want to see each individual data point (especially when multiple dimensions and measures are involved).
Circle mark – Useful when you want to see how dispersed the data is.
Shape mark – Using a shape mark, we can represent data points with custom shapes from twenty available shapes.
Map mark – Used to compare region-specific information. The geographic dimensions are added as Detail in the marks card and the measures like Longitude and Latitude are added on the row and column. Other measures or continuous dimensions can be added using marks like color, size etc.
Pie mark – Used to compare proportions.
Gantt mark – Used with date dimensions to evaluate the relative size over time.
Polygon mark – Used for connecting data points to form an area.