Importance of transitions in interactive visualisations.

I am a very big fan of transitions when presenting complex data with interactive visualisations. I believe that transitions play an important role in building a continuous narrative in audience’s mind when they are trying to understand connected series of information. To be clear, I am talking specifically about transition of data between the stages of visualisation and not the transition of the canvas of the visualisation. Today lets look at one of my favourite visualisations of all time – this brilliant interactive one by NYtimes, showcasing the budget proposal made by US government in 2012

The story here starts with showing whole budget along with the scale of 900bn budget deficit proposed, then we move to see that the most of the spending is mandatory over which the govt. has no control and the smaller discretionary spending is the one which we are having the discussion on, then we move to see these discretionary spending categories compared with each other to the gainers and losers from last year and finally we see them put together along with the mandatory spending to complete the picture.

The amazing thing about this graphic is the way the circles (departments / budget categories), which are the basic unit of the analysis, move between the stages of the story – specially from step 2 to step 3. Not only it reinforces the concept of mandatory spending it also prepares us to what we are going to be see in the next stage. This half second transition fundamentally changes the clarity and legibility of the whole story for a casual audience.

I am currently working on a medium sized dataset trying to filter it with various rules to produce a final number and this kind of visualisation seems perfect to show the changes in the results as I move to different stages of filtering. I will be posting on the progress and stay tuned for the updates.