Examining Science Tools as Mediators of Students' Learning about Circuits.

Uses a Vygotskian framework to examine students' (n=26) use of tools in a ninth-grade physical science classroom during a unit on electric circuits. Indicates that conceptual progress may be hindered by students' need to first understand the tools in terms of everyday application. Advocates selection of laboratory tools and activities that match students' zone of proximal development and everyday experiences. Contains 37 references. (Author/WRM)