[jwatte]

If Haskell is better than Python, then writing the first version in Haskell and the second version in Python should yield two versions that are closer in quality than if you did the reverse order. Assuming you can measure quality, this is a totally valid hypothesis to test!

[pekk]

Additional hypothesis: the result of this test depends strongly on which one you are more familiar with and which one you prefer. If I hate writing Cobol, I'm going to spend that part of the test pining for the other language and not using whatever the up-to-date idioms are for making Cobol manageable, but just fighting Cobol until I can switch to the language I really wanted to use.

So, anyone doing this should consider trying to get a sample of people who are more or less indifferent between the options, so they don't sabotage the test