Allan Wigfield examines Eccles et al.'s (1983) expectancy-value model of achievement motivation from a developmental perspective. He explores how recent research on young children's competence beliefs, success expectancies, subjective task values, and achievement goals can be integrated into the model. The focus includes changes in the factor structure of competence beliefs and values, age-related changes in the mean levels of these constructs, and shifts in children's conceptions of ability and subjective values. Wigfield also discusses how achievement goals are conceptualized in the model and how other researchers view them. He considers changes in the relationships among competence beliefs, subjective task values, achievement goals, and achievement behaviors. Expectancy-value theory is a key perspective on achievement motivation, starting with Atkinson's (1957) work and continuing with contributions from Battle, the Crandalls, Feather, and Eccles, Wigfield, and colleagues. The theory posits that individuals' expectancies for success and the value they place on succeeding are important determinants of their motivation to perform achievement tasks. Atkinson (1957) defined expectancies as individuals' anticipations of success or failure, and value as the relative attractiveness of succeeding or failing on a task. More recent researchers have expanded these definitions and discussed how expectancies, subjective task values, and other achievement beliefs influence motivation and achievement in educational settings. Wigfield and Eccles (1992) reviewed research on subjective task values and extended Atkinson's model. They focused on Eccles et al.'s (1983) expectancy-value model of achievement choice, which was developed to understand performance and choice in mathematics among early adolescents. The model suggests that children's achievement performance, persistence, and task choice are predicted by their success expectancies and the value they attach to success. These expectancies and values are influenced by achievement-related beliefs, including goals, self-schemata, and task-specific beliefs about ability and task difficulty.Allan Wigfield examines Eccles et al.'s (1983) expectancy-value model of achievement motivation from a developmental perspective. He explores how recent research on young children's competence beliefs, success expectancies, subjective task values, and achievement goals can be integrated into the model. The focus includes changes in the factor structure of competence beliefs and values, age-related changes in the mean levels of these constructs, and shifts in children's conceptions of ability and subjective values. Wigfield also discusses how achievement goals are conceptualized in the model and how other researchers view them. He considers changes in the relationships among competence beliefs, subjective task values, achievement goals, and achievement behaviors. Expectancy-value theory is a key perspective on achievement motivation, starting with Atkinson's (1957) work and continuing with contributions from Battle, the Crandalls, Feather, and Eccles, Wigfield, and colleagues. The theory posits that individuals' expectancies for success and the value they place on succeeding are important determinants of their motivation to perform achievement tasks. Atkinson (1957) defined expectancies as individuals' anticipations of success or failure, and value as the relative attractiveness of succeeding or failing on a task. More recent researchers have expanded these definitions and discussed how expectancies, subjective task values, and other achievement beliefs influence motivation and achievement in educational settings. Wigfield and Eccles (1992) reviewed research on subjective task values and extended Atkinson's model. They focused on Eccles et al.'s (1983) expectancy-value model of achievement choice, which was developed to understand performance and choice in mathematics among early adolescents. The model suggests that children's achievement performance, persistence, and task choice are predicted by their success expectancies and the value they attach to success. These expectancies and values are influenced by achievement-related beliefs, including goals, self-schemata, and task-specific beliefs about ability and task difficulty.