Evaluation, Stats & Pizza

The "Pizza Exercise."  This was an exercise undertaken in my PPE class to aid in understanding program evaluation stats and analysis...what are the different kinds and what can they used for: Paired-t and student-t tests, mean, mode, medium, etc.

Which pizza is best?

Now if only this exercise included real pizza, that would have made it a whole lot more fun!  Nonetheless, it was still effective in demonstrating data collection and translation into useful statistics for reporting.  Comparing two pizzas with with the same topping, "pizza A" and "pizza B," I learned that degrees of freedom  for the tests means (n-1) sample size and that this is a standard sample size number calculation.  Another thing, that I gleaned from this exercise was the importance of noting variables for experiments.  For example, if participants ate two slices of pizza A and then two slices of pizza B, eating the first two slices may influence how much of pizza B they eat because they could be full after the first set.  Or other influencing factors could be time of day of consumption, people who don't eat pork, how hungry people are, etc.

 I can't say that I feel exactly confident in using stats and data analysis in program evaluation, but I don't feel so left in the dark anymore.  This is certainly something I will need to dig a little deeper into for my own projects at work and for programs that will be designing.