How do instructors guide students to discover mathematical content? Are current explanatory models of pedagogical practice suitable to capture pragmatic essentials of discovery-based instruction? We examined videographed data from the implementation of a natural user interface design for proportions, so as to determine one constructivist tutor's…

Running experiments and grabbing experimental data are great ways to learn and teach science and mathematics. Data grabbers are instruments that capture physical data in electronic form for graphing and analysis in graphing calculators and computers. Describes some data grabbers and points to items in their gigantic support system. (PVD)