Using a quartet and variations to teach data analysis

Data analysis can be a tricky business, fraught with pitfalls to trap the unwary. In teaching data analysis, I have found that well-constructed data sets can illustrate some of these pitfalls effectively. My general strategy is to present students with the data in a computer lab setting and ask them to do an analysis then and there. I do not tell them the data present a pitfall. Whether anyone successfully avoids the pitfall or not, I immediately follow up with a discussion of the data and the pitfall.