Research statistics question?

Question

I am comparing the marks of students (n=250ish) who undertook a course this year, with those of students who undertook the same course in 2007 and 2006 to determine if an intervention (implemented this year) had any effect.

Other than Mean, median and SD, what else should I be using?

Answer 1

Depending on what your results look like, I might show the change in Chebyshev's Inequality or The Empirical Rule Percentages (how close they were to the actual standard deviation averages) between the years and see which group benefited the most from the intervention.  You might look at the number in the top 10% from each year and draw some conclusions on whether or not the intervention worked for this group between years.

Best of Luck!