Monday, December 22, 2014

Justin Wolfers' "A Persuasive Chart Showing How Persuasive Charts Are"

Wolfers (writing for the New York Times) summarizes a study from Wansink and Tal (2014) in which participants were either a) presented with just in-text data about a drug trial or b) the text as well as with a bar graph that conveyed the exact same information. The results can be read below:


According to Wansink and Tal, the effects seems to be strongest in people who agreed with the statement "I believe in science". So, a graph makes a claim more "sciencier" and, therefore, more credible? Also, does this mean that science believers aren't being as critical because they already have an underlying belief in what they are reading? 

I thinks this is a good way of conveying the power of graphs to students in a statistics class as well as the need for better scientific literacy/statistical consumerism/skepticism. I think it is also a good example of Elaboration Likelihood Model

Finally, can we take just one moment to discuss the name of the original research article, Blinded with science: Trivial graphs and formula increase ad persuasiveness and belief in product efficacy. I'm always a fan of the "<funny cultural reference>: <serious science-y stuff>" naming convention oft used in scientific articles, and this is a real gem.