This article presents a cohesive, empirically grounded categorization system differentiating the types of generalizations students constructed when reasoning mathematically. The generalization taxonomy developed out of an empirical study conducted during a 3-week teaching experiment and a series of individual interviews. Qualitative analysis of…

Using data from a nationwide, large-scale experimental study of the effects of a connected classroom technology on student learning in algebra (Owens et al., 2004), this dissertation focuses on challenges that can arise in estimating treatment effects in educational field experiments when samples are highly heterogeneous in terms of various…