There are three obvious outliers in the scatter plot and the supporting article for the data set explains that these are partial sales that should be removed. There is an illustration in the article's first example, a real data set of property sales in Ames, Iowa. Interactive EDA means interacting with people as well as with graphics, to learn about what unexpected features may imply and what can be done about them. They could also emphasize more the value of interacting with experts who have background knowledge of the data. Hullman and Gelman play down this initial stage, although it is where graphics can be particularly valuable. This has become more important as the data sets that can be handled have become bigger, especially in terms of numbers of variables. They are aiming to assist less statistically-experienced analysts, so this is reasonable, but they would have benefited from having worked with more advanced interactive tools and from the book Interactive Graphics for Data Analysis (Theus et al, 2008).ĭata analysis has always needed initial exploratory work to understand the data and to sort out whatever unexpected features may arise. The title of the paper refers to 'interactive exploratory data analysis.' The term ‘interactive’ means different things to different people, and the authors take a relatively limited view. Both have much to contribute and it is positive to have experts with different backgrounds cooperating. Andrew Gelman is, amongst his many interests, an active Bayesian statistician, and he emphasizes the role a Bayesian approach could play. Jessica Hullman investigates the display of uncertainty in graphics and recommends more to be done in that direction. The paper proposes ideas for improving graphical tools for users of business graphics systems, people with expertise in other fields but with less statistical knowledge. It is encouraging to see researchers attempting to formalize part of this relationship. Graphics is an important part of statistical analysis and complements modeling.

Taking Summer by Emily Bishop