Described is the development and validation of a test designed to assess the cognitive levels of Jamaican sixth graders. Instead of the usual clinical procedure, a 30-minute videotaped test was designed in order to standardize variables associated with the test's administration. The film presented situations involving seven conservation concepts including liquid quantity, solid quantity, weight, displaced volume, and horizontality. Following a trial run, the test was administered to 586 urban and rural sixth graders. Reliability and validity were examined through a test-retest procedure, factor analysis, and comparison with the results of a clinical test. The filmed test met the desired criteria. Appended is a description test situation depicted on the videotape. (WB)