Purpose
Portfolios provides a more comprehensive assessment of what students learn throughout a course than any other strategy, documenting students' mastery of conceptual knowledge and skills and providing evidence of the extent to which each individual has met the course goals. Best suited to courses which include complex, multi-faceted tasks that require the integration of multiple concepts and procedures, portfolio assessments provide each student the opportunity to demonstrate their understanding of course material and, when used longitudinally, how that understanding changes over time.

Description
Portfolios are student-prepared collections of documents that evidence understanding of important concepts or mastery of key skills, requiring students to organize, synthesize, and communicate their achievements throughout the semester. Several different types of portfolios can be used, but most variations are students' personalized collections of their work over the entire duration of the course.

General Requirements
The instructor must communicate his or her expectations to students at the beginning of the course, outlining (1) the kinds of mastery students are to demonstrate, given the goals of the course; (2) the types of materials that are considered evidence that those goals have been met, and (3) the criteria by which the portfolios will be evaluated. Appropriate scoring rubrics should be used for each type of document contained in the portfolios.

Limitations
Portfolios can be time-consuming to assess and often require multiple rubrics, one for each type of document they may contain. As such, they are best suited for courses with smaller enrollments; however, they can be modified for larger course by reducing their scope (see the variations listed below) and tightly structuring their format to insure some level of uniformity. Assessing on an assignment-by-assignment basis is more reliable than assessing on a portfolio-by-portfolio basis³⁷. Because most portfolios include work completed outside of class, issues of academic dishonesty may arise.

Variations
Showcase Portfolios. One way to alleviate the time-consuming nature of portfolio assessment is to use "showcase portfolios," which include only a limited number of key documents. Some flexibility can be attained by structuring the portfolios around student selection rather than particular assignments. For example, students may be asked to include five documents which best illustrate their work.

Checklist Portfolios. In contrast to the showcase portfolio, a checklist portfolio in comprised of a predetermined number of course assignments. Here, flexibility is attained by allowing students to choose which assignment they feel best represents their understanding from a list of appropriate candidates provided by the instructor.

Example Research Studies

• Calvani, Sorzio, & Varisco (1997)
• Nystrand, Cohen, & Dowling (1993)
• Slater (1997)

Additional Resources

• Collins, A. (1992) Portfolios for science education: Issues in purpose, structure, and authenticity. Science Education, 76(4): 451-463.¹⁰
• KMI FolioOne: Digital Portfolios
• Knight, M. E. (1994). Portfolio assessment: Application of portfolio analysis. London: University Press of America.²⁸
• Kuhs, T.M. (1994) Portfolio assessment: Making it work for the first time. The Mathematics Teacher, 87(5): 332-335.³¹
• Slater, T.F. & Astwood, P.M. (1995) Strategies for grading and using student assessment portfolios. Journal of Geological Education, 45(3): 216-220.⁴⁶