Friday, March 28, 2014

Inline Filtering using Tableau "Size" Calcs

This trick was too good not to pass up - Andrew Hill, Sales Consultant extraordinaire from Tableau, came up with this recently. Great stuff, Andrew!

The way it works is so simple and elegant. We use Tableau's built-in Size() function to filter certain sheets on a dashboard. We then use the built-in "keep only" feature on the tooltip. As the Size() changes, the sheets filter or disappear. Size() simply means "number of answers that the database gave us."

Wednesday, March 19, 2014

IPEDS Revisited

File under "how to break every Tableau rule in the book and thus create a poorly performing dashboard". Armed with a 70,000 row dataset from (specifically, the IPEDS longitudinal data set) I used parameters to allow the end user to select their desired metrics for correlation. I also have way too many filters on the filter shelf. The basic problem is that NCES has hundreds of metrics, all poorly named, all arcane, all requiring an excel file to look up their data definition. Many of them are ragged, meaning not all schools reported in all years. A brief scan of the metrics also shows me that definitions of metrics themselves change over the years.

I'm curious as to how other might solve this problem. I considered reshaping the 70k rows but with the number of metrics, it would end up in the tens of millions. Further, I would have a data model that is "too reshaped" or "too tall and narrow" for correlations.

If you are familiar with the common data set around IPEDS, you will be comfy using this dashboard. If you are not familiar with it... good luck! There's also a second tab with "additional filters" to refine your IPEDS criteria.