Children acquiring languages with noun classes (grammatical gender) have ample statistical information available that characterizes the distribution of nouns into these classes, but their use of this information to classify novel nouns differs from the predictions made by an optimal Bayesian classifier. We use rational analysis to investigate the…

Herbert Walberg's interpretation of a massive collection of data on school learning is discussed as a guide for inquiry and action by individual teachers. Walberg's study shows that while no single factor can produce marked increases in academic learning, an equation employing nine variables approximately predicts reported numerical measures of…