This study compared data from an evaluation of one school district's teacher staff development programs, using the True Score Theory and Item Response theory. Participants were elementary school teachers who reported on 20 staff development programs in reading. They completed the Teachers' Perception of the Impact of a Staff Development (TPISD), which examined how they thought, felt, and taught following staff development. The TPISD was given during the spring and the fall to assess whether the initial reported impact changed once teachers applied what they learned in the classroom. Data were analyzed under the assumptions of the True Score Theory and the Item Response theory. Use of the True Score Theory for evaluating change in scores on the TPISD across 4 months provided no evidence of change. Item Response Theory analysis indicated that 26 percent of the scores changed significantly across 4 months, which is far more than would be expected by chance using a 95-percent confidence interval. By using corrected person scores obtained during the stability analysis, more certainty was gained that change in scores was due to changes in the level of the measured variable rather than changes in the measure itself. (Contains 11 references.) (SM)
Paper presented at the Annual Meeting of the American Educational Research Association (New Orleans, LA, April 24-28, 2000).