This is part of a series of posts about the 'little of visualisation design', respecting the small decisions that make a big difference towards the good and bad of this discipline. In each post I'm going to focus on just one small matter - a singular good or bad design choice - as demonstrated by a sample project. Each project may have many effective and ineffective aspects, but I'm just commenting on one.
The 'little' of this next design concerns the enhanced role of annotated captions. In the well-known work 'Gun Crimes' by Periscopic, some of the main findings of analysis are provided in captions located beneath the main chart (this exists in both years of analysis, I'm focusing here on the 2010 view).
The smart feature here is that when you click on the respective captions, this provides a shortcut for the user by automatically applying the necessary criteria in the main chart above to formulate the associated view of the data that supports the finding described.