Date: 1998-1999 Developers: Chong Ho Yu, Sandy Andrews, David Winograd, Natalie Schroeder Software: Director, Strata Instant Replay, SAS/JMP, Photoshop Media: Interactive animation

Description: There are many common misconceptions regarding factor analysis. For example, students do not know that factor analysis happens in subject space rather than variable space. Consequently, eigenvectors are misunderstood as regression lines, and data points representing variables are misperceived as data points depicting people. Subject space is omitted by many statistics textbooks and indeed it is a very difficult concept to illustrate. We developed this animated tutorial in attempt to alleviate this problem. Since the target audience is intermediate statistics students who are familiar with regression, in the program we use regression in variable space as an analogy to lead learners into factor analysis in subject space. At the end we apply Gabriel biplot to combine the two spaces together.

You can download the beta program for evaluation. The file size is large. Don't do it at home unless you have a cable modem.

• Mac version (15 meg): This is a binhexed self-extracting archive. Your browser will automatically convert the file to an executable program.

• Windows version (10.7 meg): This is a zip file. You need Winzip to decompress the file.