[seldo]

Yeah, my conclusion from the data was "senior developers know more things and have more time on their hands to tell others about those things", which is exactly what you'd expect. The more senior you get, the more your role is as guide and mentor than immediate implementor.

[brown9-2]

One of alan's points is that it is incorrect to assign behaviors of "older Stackoverflow users" to the universe of "older developers".

The population of "older Stackoverflow users" is not randomly drawn from the population of "older developers", and nothing is put forward to claim that the former is representative of the latter, so you cannot make this assumption.

[jwhite]

Exactly. The graph showing that older coders' answers are not significantly better than those of younger coders is a case in point: maybe the good older coders are too busy actually coding to spend time answering questions on StackOverflow.