As part of a multiyear research study on the preparation of educators to use assessment data for instructional improvement, the present study is a pilot test of a research-based professional development intervention for career-technical teachers. Forty-eight educators at nine sites in five states participated in a 1-day workshop followed by several months of mentoring either on site, by teleconference, or website. To extend the professional learning of the workshop, educators were mentored for several months as they developed a plan for instructional improvement. To complement the mentoring, a project-specific website was the focus of a community of practice where the participants could exchange information and create threaded discussions about the process of data-driven instructional improvement. Educators need an orientation to the website features, reinforcement for their online interactions, and specific activities to complete in a timeframe if they are to use web-based professional learning communities to the fullest. (Contains 3 figures.)