The Psychology of Learning and Motivation publishes empirical and theoretical contributions in cognitive and experimental psychology, ranging from classical and instrumental conditioning to complex learning and problem solving. Volume 49 contains chapters on short-term memory, theory and measurement of working memory capacity limits, development of perceptual grouping in infancy, co-constructing conceptual domains through family conversations and activities, the concrete substrates of abstract rule use, ambiguity, accessibility, and a division of labor for communicative success, and lexical expertise and reading skill.