Describes two studies investigating the development of recursive thinking in 60 Dutch children five, seven, and nine years of age. The first study replicated earlier research employing a verbal production procedure. The second study used verbal comprehension procedures and concluded that development appears two years earlier than indicated by the…

This article illustrates some problems faced by student teachers of biology when they try to realize the process of "didactic transformation" while planning their classes. To address these problems, a method of subject-matter analysis, utilizing hierarchical concept-maps, was introduced into the teacher training component at the Free…

In this study Dutch subjects with four different levels of expertise (24 second-year, 24 fourth-year, 24 sixth-year medical students, and 24 internists with at least 4 years of experience) studied, diagnosed, and explained four clinical cases. Diagnostic accuracy increased with the increasing level of expertise. The number of concepts used and the…