Length and Position as Pre-attentive Properties
Let's begin by focusing on Length and Position as our first two properties.
Length is really just as simple as it sounds
Length allows values to be easily measured and compared.
For this reason, length is typically used with bar graphs.
You can see how the length of the bars is a useful visual property for easily comparing the category with the most sales, and consequently the category with the fewest sales.
The way you position your data can also provide additional clarity to your viewers. For example, while length provides clarity already, further positioning our categories from most sales to least sales allows quick processing of the data being offered.
In short, length helped to compare the relative amount of sales among the categories; while position helped easily tell the rank of each category.
As you can see, pre-attentive properties provide a lot of clarity. Let's implement these properties in Tableau.