With one treated and one untreated periods, difference in differences (DD) requires the untreated response changes to be the same across the treatment and control groups, if the treatment were withheld contrary to the fact. A natural way to check the condition is to backtrack one period and examine the response changes in two pretreatment periods.…

Previous work demonstrated that 9-month-olds who were familiarized with 3-syllable strings consistent with both a broader (AAB or ABA) and narrower (AA"di" or A"di"A) generalization made only the latter. Because the narrower generalization is a subset of the broader one, any example that is consistent with the broader generalization but not the…

Presents a prototypical case illustrating what positivist research means and argues that even critics of positivist research are logically committed to propositions that can be tested only through positivist research paradigms. The relationship between the nature of a community's research enterprise and its educational provisions must be causal.…