This Digest describes matrix sampling of test items as an approach to achieving broad coverage while minimizing testing time per student. Matrix sampling involves developing a complete set of items judged to cover the curriculum, then dividing the items into subsets and administering one subset to each student. Matrix sampling, by limiting the number of items administered to each student, limits the amount of testing time required, while still providing, across students, coverage of a broad range of content. As state or provincial testing officials consider using matrix sampling, they must recognize that every test design, whether or not it involves a matrixed component, carries with it certain costs. The choice of design requires careful consideration of these costs, and every design represents a compromise in terms of one or more costs. (SLD)