At first blush that seems like a pretty insulting question, but don't worry, we're not calling you a liar – not quite. I recently read through Edward Tufte's phenomenal Visual Explanations: Images and Quantities, Evidence and Narrative and came away with a lot of great ideas and points to think about, but one really stuck with me. Data visualization not only needs to be clear and informative, it needs to be honest.
There's a lot of data display out there that is dishonest, and that doesn't imply any sort of nefarious motivation: data display is tricky, and the best of intentions can still lead to display that doesn't tell the whole story, or maybe tells the wrong story altogether. Tufte's object lesson was the investigation into the Challenger disaster.
The complete analysis of the Challenger disaster is pretty complex – the abstract is that launch day was unusually cold and the rubber rings that joined the segments of the solid rocket boosters were too cold to move into a proper seal as the rocket flexed under the fuel pressure. Fuel escaped and destroyed the seal; the plume of escaping fuel ignited and forced the booster into the main fuel tank. Robbed of its aerodynamics the vehicle fell apart under the pressure of acceleration.
The disaster itself was bad enough; worse was that Tufte posits it could have been avoided if the initial data display had been honest. That's not to say there were evil schemes involved, or people lied to get the shuttle launched on time – Tufte doesn't address those points. However the firm responsible for the manufacture of the O-rings sealing the booster presented data to NASA which was improperly displayed – it did not correctly identify the correlation of low temperature to O-ring failure.
This is part of the report to NASA examining the likelihood of failure on the Challenger's rocket O-rings. Can you tell what this is saying? Neither could anyone else.
For the complete picture you should read Visual Explanations . There's great material in there on ways to lead users through a flow, display actions and layers through illustration, and a variety of other topics. What I took away was the importance of honest data display, something we should all be sure we bring to our projects.
