Randomized experiments are often seen as the "gold standard" for causal research. Despite the fact that experiments use random assignment to treatment conditions, units are seldom selected into the experiment using probability sampling. Very little research on experimental design has focused on how to make generalizations to well-defined…

The authors sought evidence of the effectiveness of the TI-Navigator classroom networking system for the second year of a two-year research study of Texas Instruments classroom technology. This randomized control trial compared Algebra I and Geometry instruction using the TI-Navigator system, which includes the TI-84 Silver Edition graphing…