Supporting Teachers' Data-Based Individualization of Early Writing Instruction: An Efficacy Trial.

In a multiyear, multisite, randomized control trial, we examined the effects of comprehensive professional development designed to support teachers' data-based instruction (DBI) for students with intensive early writing needs. Teachers ( = 154; primarily special educators or intervention specialists) were assigned randomly to a treatment group ( = 76), in which they received tools, learning, and coaching to support their DBI implementation over 20 weeks, or to a control group ( = 78). Students either received DBI in early writing ( = 155) from treatment teachers or their usual writing instruction ( = 154) from control teachers. Treatment teachers outperformed controls on measures of DBI knowledge and skills ( = 1.57) and self-efficacy for writing instruction ( = .94), and treatment students outperformed controls on proximal and distal writing outcomes (s = .14-.29). Student characteristics (grade, special education status, English learner status, and race/ethnicity) did not moderate intervention effects. We discuss findings in terms of the importance of supporting students with intensive learning needs, the efficacy and feasibility of implementing DBI-TLC, and implications for pre- and in-service teacher training and support.