Evaluation of Project Learning Tree (PLT) involved a survey of PLT's utilization in British Columbia and the field experiment. The survey included participant observers' reports on PLT teacher training workshops, a mail survey of workshop participants, and telephone interviews with selected respondents. Two treatment conditions were effected at grades 3, 5, and 7 involving a minimum of two school districts. Both cognitive (achievement) and affective (attitude) dimensions were assessed for potential impact of the instructional intervention. The field experiment involved the development of instructional units for grades 3, 5, and 7 by classroom teachers identified through the survey as "high" users of PLT; participation in 3-day workshops at the University of British Columbia; the evaluation team and PLT facilitator's revision of the units prepared at the workshops; development of specifications and preparation of tests to assess the units' cognitive and affective components; identification of field sites and teacher recruitment; attendance of participating teachers at training workshops offered by the PLT facilitator and evaluation team; and monitoring of classroom execution and testing by the evaluation team. Overall, teacher response to the materials was positive. Delivery of instruction appeared to be most consistent at grade 5 and most idiosyncratic at grade 7. (NQA)