James Cooper is professor emeritus at the University of Virginia and lead author of Classroom Teaching Skills.

A portfolio is a carefully selected collection of a student's work designed to provide the opportunity to make very specific kinds of assessments. The two most common types of portfolios used for assessment purposes are "best-work" portfolios and "growth and learning-progress" portfolios.

Best work portfolios are a collection of a student's best products (e.g. art projects, math papers, writing assignments); they provide a sample of student work over time, across media, and for a variety of problem types. Growth and learning-progress portfolios are used to collect samples of a student's typical work over time. These portfolios allow one to assess such things as the type and quantity of errors as learning progresses, the type of thinking and problem-solving strategies used by students as they learn, and the ability of students to catch and fix their own mistakes as they progress.

For portfolios to be most effective, they should be an integral part of the classroom activities on an ongoing basis throughout the year. Using portfolios as an assessment tool requires at least the following six steps.

1. Decide on the portfolio's purpose.
The key here is to determine why you want to collect a portfolio of student work. Answering the following questions should help: Which learning objectives should be assessed? What could you and your students learn about the progress being made? Would a portfolio help determine areas of misunderstanding? Do you want to evaluate a sample of a student's best work or are you interested in assessing growth or progress? Do you wish to assess process or product? Is a portfolio the best way to obtain the assessment information you need?

2. Decide who will determine the portfolio's content.
To collect everything a student does is inefficient and makes the portfolio difficult to interpret. A carefully selected sample of work makes a portfolio manageable and easier to evaluate. Usually the teacher determines which work samples will be placed in the portfolio, but sometimes you may prefer to have students choose. A great deal can be learned about a student's ability to evaluate their own work if you ask them to select the work to be included. In either case, it is helpful to establish the criteria for determining what should be included.

3. Establish the criteria for determining what to include in the portfolio.
Which learning objectives are to be evaluated, and what work would best represent progress toward, or accomplishment of, those objectives?

Do you want a student's best work? Do you want early drafts as well as subsequent revisions, or only the final product? Do you want to see materials related to preliminary work, such as references (perhaps including those identified but not used, as well as those used in the work), note cards, outlines, and so forth? Perhaps an audiotape of interviews conducted in preparation for a report would be useful in determining how a student selects information to report.

4. Determine how the portfolio will be organized and how the entries will be presented.
How should the entries be labeled? Should there be a "container" for all entries and, if so, how will it be labeled? Would a table of contents be helpful? Besides the student's name and date of completion, what other information about an entry would be helpful? Would the student's own evaluation of each entry provide useful information? Should the entries be organized chronologically or grouped to represent different learning outcomes or different kinds of problems? If there are several categories of entries, how many entries should be placed in each category? When are the entries to be placed in the portfolio? These questions, and others that will be dictated by the type of portfolio being developed, must be addressed before students begin the work that will eventually end up in the portfolio.

5. Determine when and how the portfolio will be evaluated.
Will you be evaluating entries at several points in time as the portfolio takes shape (formative evaluation), or will the evaluation only occur once the entire portfolio is complete (summative evaluation)? Will the teacher or the student evaluate the portfolio, or will the teacher and the student do the evaluation together? Have criteria for evaluating been developed, or has a scoring rubric been designed? Will a single score (or grade) be given, or will a more analytical assessment be made? How much and what kind of feedback will be given to the student? Would written comments be more helpful than a score or grade?

6. Decide how the evaluations for the portfolio and its contents will be used.
Will the evaluations be used to determine a grade that will be a part of the report card grade? Will the evaluation results be used primarily to assess final achievement, or will they be used to determine progress? Will the findings be used to help students learn from their efforts? Will your teaching strategies change as a result of how effectively and/or efficiently students are learning? What information should be given to the parents that would help them better understand the portfolio and its contents? Will the contents be judged on the basis of established criteria, or by comparing a student's work to the work of other students? Will comparisons be made across time, comparing a student's early work with his or her later work? These and similar questions should help you to determine the kind of judgments and decisions that will be made on the basis of the information obtained from portfolio assessment.

A portfolio can be a very powerful tool if it is fully integrated into the total instructional process, not just a "tag-on" at the end of instruction. Remember too, that all kinds of materials can be organized into portfolios. Besides the obvious paper-and-pencil entries, one can collect samples of art objects, 3-D models, audiotapes and/or videotapes of performances (music, speeches, interviews), and samples of a student's thinking process (written or recorded). Be creative, but always ask these very important questions: How will samples of students' work help to assess student performance or progress? How will such an assessment help improve my teaching and my students' learning?

Reprinted with permission from Classroom Teaching Skills, Seventh Edition. Copyright © 2005 Houghton Mifflin Company. All rights reserved.