摘要:Teachers' self-efficacy and outcome expectancy have been consistently associated with student achievement. This research examines changes in these constructs for K-12 inservice teachers who participated in a two-week summer professional development experience designed to promote the use of outdoor spaces for environmental science instruction. The investigators used the Science Teaching Efficacy Belief Instrument, version A (STEBI-A) (Riggs & Enochs, 1990), which was modified to include statements about outdoor science teaching. Pre- and post-assessment results for the 22 teachers who completed both assessments indicate significant increases in outcome expectancy scores for classroom and outdoor science teaching, as well as self-efficacy scores for outdoor science teaching, from pre- to post-test. An unexpected observation was the reported decrease in self-efficacy for traditional science teaching over same period. The results are examined further and explained using supporting data from the professional development, specifically, assessments on participants' beliefs about outdoor instruction, audio taped small group discussions, reflective journal entries, and researcher notes from classroom observations. Recommendations for PD planning and future research on teacher self-efficacy and outcome expectancy are presented.