I get where they are going, and I agree with the rest of their premise. i just think that particular question is flawed in that both answers are technically correct
The ball being 10 cents isn't technically correct, the question isn't ambiguous at all. This question was developed through decades of research in behavioral economics, it's used in a myriad of inventories controlled for understandability.
Yup. But I think the point here is that it's a question designed to trick the person into thinking that they're being asked what Kao was talking about, but while actually asking something slightly different. I don't think most people answer that question thinking "a dollar is a dollar more than 10 cents". They answer the question thinking "A 10 cent ball plus a dollar more equals the total price for a ball and bat". The issue isn't really with a math error, but with an interpretation error. But the question is specifically designed to increase the odds of someone reading that question for the first time making exactly that error.
The value of such experiments isn't to make grand claims like "smart people are actually stupid", but "lean how to avoid questions which can be interpreted differently than you intend". The entire field of technical writing is basically devoted to learning what phraseology methods will result in such confusion and then avoid them. I guess from a psychological perspective, it's useful to know what sorts of questions act as tricks to human minds, but I wouldn't put much more weight on it than that. Edited, Jun 18th 2012 1:28pm by gbaji