We are shameless magpies here at Thunderfly, and so I am never happier than when passing on a tool or tip that I think people might find useful.  And so it is that I'd like to highlight a tool which Warren and I have mentioned during our courses, but not yet on the blog - the Junk Charts Trifecta.

The interior decoration of graphics generates a lot of ink that does not tell the viewer anything new. The purpose of decoration varies — to make the graphic appear more scientific and precise, to enliven the display, to give the designer an opportunity to exercise artistic skills. Regardless of its cause, it is all non-data-ink or redundant data-ink, and it is often chartjunk.

The blogger behind Junk Charts, Kaiser Fung, has said he aims to recycle the chart junk he encounters into junk art. The blog showcases the occasions on which heinous crimes against data visualisation are brought to his attention, and he does his best to extract the meaning (like sunlight from a cucumber, as Farquarson would have it) and display it in a more meaningful way.  

Now, we've covered checklists (including one from the estimable Stephen Few, which Warren put to good use) before, but Fung has developed this triangular checklist, which he calls the Trifecta, and which might conceivably be easier on the eye if you print it and put it up by your desk.  Successful data visualisations have all three elements in harmony, and Fung checks both the original visualisations, and the ones he develops to replace them, to ensure they meet the criteria.

You can address the three elements in any order, but perhaps it makes sense to start at the top and ask what the question being asked is - what question is the data answering?  This was something mentioned by John Kay in his series of superhero recommendations.  You could be overstepping the mark if you use data to assert something that it doesn't actually show.

The second point of the triangle asks what the data says.  This is the section where your expertise or area of interest guides you to pick out the important information that you wish to communicate.  It is hard to offer concrete guidance in this area; this is where we remind you that you are the expert, and to have the confidence in the decisions you make.

Finally, the trifecta asks you to check whether the chart or figure you've designed communicates both of those aspects.  If all of these three elements are working for you, you're onto a winner.