Performance assessment offers an approach to assessment different from that of group-administered standardized tests by documenting activities in which children engage on a daily basis. Flexible enough to reflect individual academic achievement and designed to evaluate elements of learning not captured by standardized tests, the Work Sampling System offers an exemplar of how performance assessment works in early childhood and the primary years. This system assesses and documents children's skills, knowledge, behavior, and accomplishments across a variety of education domains and as manifested on multiple occasions. It consists of three components: (1) developmental guidelines and checklists; (2) portfolios; and (3) summary reports. The developmental guidelines and checklists assist teachers in observing and documenting children's progress across seven domains of development. These domains are divided into functional components, each of which contains performance indicators that represent important skills, knowledge, behaviors, and accomplishments. The guidelines that accompany the checklists make the process of observation more reliable and consistent. The checklists and guidelines create a profile of children's individualized progress. Portfolios, which are collections of children's work, provide a rich documentation of each child's experiences throughout the year. In the Work Sampling System, portfolio collections are based on two types of work: core items, which represent a particular area of learning within a single domain; and individualized items, which offer examples of children's work across domains. Summary reports, completed three times a year, consist of performance and progress ratings in each domain, and teachers' reflections and comments about the child's development. They are a means of translating the information in the checklists and portfolios into a more easily understood document for parents, teachers, and administrators. Contains seven references. (BC)