I am using SPSS 17.0, and have a dataset that contains pre- and post-test scores for about 1,800 individuals. 1,000 of these individuals were in the treatment group, while approximately 800 were in a control group. I'd like to create a scatterplot or something similar.
I don't want to plot pre-test as x and post-test as y, however, but rather want the x-axis to be the category (pre or post), and want the y-axis to contain the 2 scores for each individual. I was able to accomplish something close using an overlay scatterplot, but it combines both the treatment and control groups together. I need to identify (with different colors/shapes) which points represent someone in the treatment group and which represent someone in the control group.
Additionally, and this may be complicated, I'd also like to create 2 lines (one for treatment and one for control) which show the general trend in the points, by going from the mean of the pre-test (for tx and for control group) to the mean of the post-test. To better clarify, I've attached a drawing of what I'd ideally like the final graph to look like. I'm open to any suggestions you may have (including if I need to restructure my dataset)! Thank you!
You do not have the required permissions to view the files attached to this post.