Instructional Science 25: 133–150, 1997. 133 c 1997 Kluwer Academic Publishers. Printed in the Netherlands. The unit of analysis for situated 1 assessment MICHAEL F. YOUNG, JONNA M. KULIKOWICH and SASHA A. BARAB University of Connecticut, U-4 UConn, 249 Glenbrook Rd., Storrs, CT USA 06269-2004; e-mail: myoung@UConnVM.UConn.Edu Abstract. We begin with a discussion of contemporary approaches to assessment highlighting their reliance on a static, linear model of knowledgeable performance. Next we describe an ecological psychology approach to problem solving. Then, we propose the adoption of an agent-environment interaction as the unit of analysis. We continue by describing the problem- solving process from an ecological psychology perspective, to clarify the “intentional unit”. We close with a discussion of functional validity, the value added by access to assessment information during the problem-solving process. Key words: situated learning, assessment, problem solving There has been considerable discussion of the challenge to information processing and schema theory posed by research on situated cognition (e.g., Special Issue of Cognitive Science, 1993). At its heart, this debate comes down to a difference between the predominant metaphor of learner as processor versus the ecological psychology metaphor of learner as detector. The processor view, as characterized by Vera and Simon (1993), holds that knowing and learning are mediated by symbolic representations in the head. The detector metaphor, preferred by James Gibson (1986), reduces the process of knowledgeable performance from three stages (input, symbol- based process, output) to two (perception, action). To work as a detector, a learner is assumed to be immersed in a changing, dynamic environment, and is described as being “tuned” to detect regularity, invariance, from the continuously changing field. There is no symbolic intermediary, not even a heavily compiled one, and the agent is considered to have developed (through phylogeny as well as ontongeny) to resonate to the detected invariances; that is, perception is direct. From this perspective, knowledge (as traditionally represented in a knowledge base) is an epiphenomenon of an agent interact- ing with an environment, in that knowledgeable behavior is co-determined 1 The use of the term “situated assessment” is used here to make contact with a literature on situated learning, situated cognition and situated activity. It is not meant to imply that some assessments are situated and others are not: all assessment occurs in some context, a situation.