Primary trait scoring is an approach for evaluating constructed responses, in which scores are based on one or more specific aspects of performance that are essential for the successful completion of the tested task. Primary trait scoring is most typically associated with writing assessment and was originally developed by Richard Lloyd-Jones and colleagues in the early 1970s to score [Page 1296]writing in the U.S. National Assessment of Educational Progress (NAEP); since then, it has been used in a variety of contexts such as task-based assessment of second languages. As originally formulated, a key assumption of primary trait scoring was that different types of writing tasks and contexts have different criteria for success. Therefore, it is necessary during test design to carefully define the types of ...