This software allows you to extract data from published graphs. There is a web-based app and a downloadable version. First, you provide the software with a picture of the graph in question. Then you give it two points on the x-axis and two points on the y-axis for reference. Then you click on the points on the graph that you want to extract. The points are put into a .csv file.
This case study starts by the simple comparison of the prices of houses with and without fireplaces and extends the analysis to examine other characteristics of the houses with fireplace that may affect the price as well. The intent is to show the danger of using simple group comparisons to answer a question that involves many variables. The lesson shows the R code for doing this analysis; however, the data and the model could be used with another statistical software.
A reference for analyzing large, complex data sets. Helpful for various levels of students.