Rubrics - "Rubrics are tools that guide the evaluation of student work and clarify student understanding of expectations for quality work. Generally, rubrics specify several categories of significance in achieving quality. In addition, a rubric describes how various levels of quality in each of the designated categories would look. The most effective rubrics help students explore qualitative differences in their work, rather than quantitative differences. For example, it is not necessarily an indication that a student has done better work if he or she has used five resources rather than four. A more appropriate indication of quality is that the student synthesized understandings from several reliable sources." (Tomlinson & Strickland, p. 355).
C. Tomlinson & C. Strickland (2005) Differentiation in Practice: A Resource Guide for Differentiating Curriculum Grades 9-12. ASCD.