ABSTRACT
The meaning of the term “development” continues to engage scholars in philosophical and theoretical debate (e.g., Collins, 1982; Featherman, 1985; Ford & Lerner, 1992; Harris, 1957; Kaplan, 1983; Lerner, 2002, 2006; Overton, 1998, 2003, 2006; Reese & Overton, 1970). The existence of the debate is itself indicative of a key feature of the meaning of the term: Development is not an empirical concept. If it were, inspection of a set of data would indicate to any observer whether development was present. However, different scientists can look at the same data set and disagree about whether development has occurred.
