In the first of two experiments, we demonstrate the spread of a novel form of tool use across 20 "cultural generations" of child-to-child transmission. An experimentally seeded technique spread with 100% fidelity along twice as many "generations" as has been investigated in recent exploratory "diffusion" experiments of this type. This contrasted…

In an earlier study, we had tested if observing a collaboration model, or alternatively, following a collaboration script could improve students' subsequent collaboration in a computer-mediated setting and promote their knowledge of good collaboration. Both model and script showed positive effects. The current study was designed to further probe…

This discussion article addresses the nature of models used in hydrology. It proposes a minimalist classification of models into two categories: models built on data from observations of the processes involved, and those for which there are no observation data on any of these processes, at the scale of interest. (LZ)