Reports on a study that uses psychometric modeling to rank the appeal of a variety of children's astronomical ideas on a single uniform scale. Findings support the view that alternative conceptions may be markers of progress toward understanding. Contains 82 references. (DDR)

Differentiating between time-series design and time-series analysis, examines design considerations and reanalyzes data previously reported by Mayer and Kozlow in this journal. The current analysis supports the analysis performed by Mayer and Kozlow but puts the results on a somewhat firmer statistical footing. (Author/JN)