A key component of assessment in the project-based learning process is the use of rubrics. A comprehensive rubric includes criteria that specify learning goals that demonstrate mastery of course outcomes, as well as criteria for those skills necessary to demonstrate expertise in the field, such as inquiry, argumentation, source analysis, inferencing and reasoning. Most projects have multiple rubrics for a variety of purposes. Rubrics may be used to guide students on depth and breadth of content research, on historical skills such as persuasive writing or contextual analysis, or on presentation skills. Often, skills-based rubrics can be developed once and used as needed depending on project parameters. For example, students may write an essay on historical context for one project, while in another they are writing an expository essay on laws relating to property rights in medieval London. Because the purpose for writing is different (context versus information), different rubrics are required. However, once the rubric for expository writing is developed, it can be used for any project in which expository writing is required.

Using rubrics does not guarantee that students will be invested in self evaluation. In order for rubrics to facilitate learning and enhance metacognition, explicit instruction in the use of rubrics to evaluate their work must be given along with related content knowledge. Without a sufficient knowledge base, students will not be able to effectively use the rubric for their benefit. It is the integration of both metacognitive skills in using rubrics for analysis and content matter during instruction that enhances knowledge building.

While rubrics can be used by the instructor to assess project outcomes, the most important use of rubrics are for self-evaluation, feedback, and revision. Well designed rubrics serve as a guide for students, and with continued use enable students to become adept at monitoring their own learning.