Analyzes the logical basis of testing developmental order hypotheses with categorical measures. Argues that depending on whether saltatory or continuous developmental changes are being assessed, the observed relationship between categorical measures yields different types of information about developmental ordering. Maintains that when change is…

Shares three ideas concerning how to evaluate the practical importance of developmental findings to make them more useful to policymakers: (1) statistical significance tests need to be accompanied by effect size estimates; (2) meta-analyses are helping in using all existing data when examining issues involved in policy debates; and (3) researchers…

Suggests that testing developmental ordering hypotheses is difficult because rare use of ratio scales prevents direct comparison of measures. Demonstrates that the observed data pattern is constrained by the underlying relationship--although observed data pattern may not reflect the exact relationship, it limits possible relationships. Shows the…

Describes issues which are common to all research methodologies and some that were unique to the assessment techniques used in the Child Development Project (CDP) in San Ramon, California. Looks at the limited amount of time given assessments and the "fluid" nature of measurements. Notes that CDP issues involved observations,…