Valencia, S. W., & Calfee, R. (1991). The development and use of literacy portfolios for students, classes, and teachers. Applied Measurement in Education, 4(4), 333-345.
Valencia and Calfee survey the general issues behind the use of portfolio assessment in (and beyond) the public school literacy classroom. The idea of portfolios has been drawn from the professional realms where portfolios of past work are used to judge the competence of an individual with respect to a specific domain or activity. Literacy portfolios are a kind of "purposeful collection of student work and records of progress and achievement assembled over time" (p. 335). They are different from professional portfolios in that the work standards and goals of a literacy portfolio are generally created and imposed by someone other than the student, and they are used by different audiences to make decisions about the student's abilities. Portfolios have been adopted because of the authenticity of the tasks involved, alignment with curricular goals, and the depth of individualized information they provide across time and contexts. They also tend to shift the ownership of instruction to the classroom. Portfolios can take the form of showcases (featuring a student's best, self-selected work), documentations (showing evidence of student work and progress across time, but with no selective or evaluative process), and evaluations (which tend to be standardized, directed, and rated by teachers or administrators).
Difficulties in the use of portfolio assessments center on: the ability and training of teachers for implementation of effective portfolios; validity of portfolios for making inferences about individual students and groups of students; reliability of portfolio assessment across tasks, raters, and time (especially when variability in tasks and contexts is assumed from the outset); resources, time, and money requirements; and reporting of assessment information to other interested audiences.
Teacher's class portfolios can offer a means of reporting assessment information and maintaining decision-making accountability. These documents should include class-level summaries, detailed notes on individual progress and work, and a comparison of curricular goals and demonstrated outcomes (leading to revision and extension of instruction). Teachers can use these portfolios to share valuable, in-depth information with interested parties. Institution of portfolio assessment will not alone engender the desired changes. Implementation should instead be a process that is system-wide and related to instructional improvement in general.
