This chapter provides an overview of basic research on memory and forgetting. Of course, that is a tall order given that there are entire books written on the subject (e.g., Baddeley, Eysenck, and Anderson, 2009; Tulving and Craik, 2000). Therefore, by necessity, we will be selective. Nevertheless, we will try to provide coverage of a wide range of memory phenomena, keeping in mind the interests of the readers of this book. Our goal is to provide an overview of empirical research and current theorizing that will benefit researchers interested in individual and team skill decay. We begin with three classificatory distinctions made in the memory literature-short-term versus long-term, implicit versus explicit, and episodic versus semantic memory. Next follows a discussion of standard memory tasks with a focus on recall and recognition and a related distinction between recollection and familiarity processes. The remainder of the chapter examines several factors that influence retention and the mechanisms of forgetting. The former includes encoding specificity and distinctiveness, prior knowledge, embodiment, and desirable difficulties. The latter begins with consideration of the construct of decay. Although expedient as a colloquial description of what happens to a memory over time, decay is inadequate as an explanation of forgetting because the mechanism by which a memory weakens is never specified. We also consider interference during storage (consolidation) and interference at retrieval. Interference at retrieval comprises several related constructs including retrieval failure, cue overload, and retrieval-induced forgetting. Finally, we discuss recent research on a possible suppression mechanism that may underlie certain forms of intentional
forgetting. We conclude with practical recommendations for the skills researcher and the practitioner that include the use of formal models.