I recently came across this post that highlights the importance of seeing what isn’t in the data: http://blogs.hbr.org/2014/05/visualizing-zero-how-to-show-something-with-nothing/
In Tableau, rows, columns and marks are defined by records of data. That means that most of the time, you are limited to showing what is in the data. But there are a few options for showing what isn’t.
- Show missing rows or columns. From the menu select Advanced > Table Layout > Show Missing Rows / Columns. What this will do is show headers for the domain of values present for the discrete field defining the header. This is context sensitive, so you can limit the range with a context filter.
- Turn on “Show Missing Values” for dates and bins. (Right click or use the drop down menu on the field in the view and select Show Missing Values). Since Tableau knows the min/max values and increments for a date or bin that defines a Row/Column header, it can fill in missing values and thus show you what’s missing.
- Pad the data on the back-end. You can supply missing values by joining or unioning to give you the complete domain of a dimension.
- Pad the data in Tableau. This one is harder as it requires an understanding of how different table calculations interact with dimensions on various shelves. But sometimes, it’s your only option (e.g. you can’t touch your data source because it’s cloud based or locked down). If you are interested in knowing more, do a search for Tableau along with the key words “Data Densification”, “Domain Padding” or “Domain Completion”. Also, check out this great video featuring Joe Mako: http://vimeo.com/107354333
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