A scientific study conducted by REL Northwest in 74 Oregon elementary schools showed that the 6+1 Trait Writing model caused a statistically significant increase in student writing scores during the year in which it was studied.

REL Northwest’s study examined first-year implementation of the model, in which teachers were provided with additional writing instruction and assessment strategies that were intended to complement whatever writing curricula and strategies were already in use at their schools. An Investigation of the Impact of the 6+1 Trait Writing Model on Grade 5 Student Writing Achievement, published in December 2011, found that when implemented under similar conditions the writing model could be expected to raise the average level of fifth-grade student writing achievement from the 50th to the 54th percentile. The two-year randomized controlled trial involved 102 teachers and 2,230 students in the treatment condition and 94 teachers and 1,931 students in the control condition.

According to previous research, including National Commission on Writing studies in 2004 and 2006, the development of academic writing skills is essential to student success in secondary and postsecondary education and in an increasing number of high-wage jobs. In addition, the remediation of writing problems currently imposes significant costs on public and private organizations, including postsecondary institutions. Grade 5 was chosen as the target population for the study based on the importance of developing academic writing skills at that grade level. Fifth-grade writing instruction typically focuses on learning expository and persuasive writing—skills that are essential to students’ success in all subsequent grade levels.

The Trait writing model emphasizes instruction in which teachers and students analyze writing using a set of characteristics, or “traits,” of written work, including: ideas, organization, voice, word choice, sentence fluency, and conventions. Use of the model is widespread throughout the United States and in several countries.

In addition to the analysis of students’ holistic writing scores, the study included exploratory analyses of student performance on six specific outcome measures of particular writing traits. Use of the model increased student scores on three writing traits—organization, voice, and word choice. For the other traits the mean outcome score of students in the treatment condition was higher than that of students in the control condition, but these differences were too small to be considered statistically significant.

Although the research team for this study was employed by Education Northwest, the organization that developed and markets the 6+1 Trait Writing model, numerous steps were taken to ensure the transparency of all research processes and to limit the possibility of bias.