Sometimes, it can be very helpful to reduce the volume of data you are working with by making selections against fields in your data, which state:

IF column = x, then include, ELSE exclude

Here you are testing if the condition is true or false and filtering out the false values. This conditional logic can be applied to any column or value in your data source and is enacted using the Filter menu at the top right corner of the data source connection screen. Through this method you can focus on the data you are particularly interested in and lessen the impact of working with large data sources on your computer too. This is often called ‘reducing the ‘noise’ because the design processes are quieter for you and your laptop.

|Image: Data source connection screen: Tableau filter menu option |

Let’s view an example of applying a filter on the field Country on retail sales data. This might mean selecting only a small number of specific countries, excluding certain countries, choosing countries according to part of the name, a condition or dynamically picking up the top 5 countries by quantity sold.

| Image: Example of applying a filter on a Country field |

There are many other examples of conditional logic in Tableau, such as creating calculations, dynamic filtering, parameters, sets, groups and interactions from one viz to another.

Next, let’s leave the data source connection view aside and turn your attention to the more visual part of Tableau.