Data on the implementation of state-mandated portfolio assessment guidelines were collected in a class of 25 fourth-grade students in a Kentucky urban school, using participant observation, interviews, and document analysis. The use of computers as word processors was found to facilitate students' ability to read their work aloud to their class, supporting student self-esteem and pride in their writing in this and other ways. The production of typed texts for portfolio inclusion rather than handwritten samples was found to reduce the role of handwriting and spelling (low priorities according to state guidelines) in portfolio evaluation. Several techniques for helping students develop quality materials for their portfolios are discussed, all of which appear to be time-consuming but effective. The use of substitutes in the classroom one day each week to provide the regular teacher with time to help students with portfolio materials led to problems in classroom behavior on such days, but helped generate stronger portfolios. The challenge of balancing the school's schedule the state's portfolio requirements, and the students' day-to-day needs is explored in the larger context of assessment-driven elementary education. (Contains 25 references.) (PB)