I am interested in running statistical analysis of quiz answers at the completion of a quiz and displaying the result to the student. One of the items I'd like to calculate would just require some simple math, sensitivity and specificity. A secondary desire would be to display an ROC curve based on the answers given, but I'd have to invoke R stats app, state, PSPP, or something similar to generate the curve.
I know that PHP can invoke command line applications, but I really just don't know where to start to set something like this up. Can any of the PHP aficionados weigh in here?