Two- and 3- year old children are smart noun learners. Indeed, they are so skilled that they often need to hear only a single object named to correctly generalize that name to other members of the category. Young children's facility in mapping nouns to categories is particularly remarkable because nouns name objects in many different kinds of categories, categories of substances, people, animals, artifacts. This research tests the hypothesis that children learn how to learn words by learning words. The idea is that each word learned makes children ever smarter and ever faster word learners. The project tests four hpotheses: 1. Early learned nouns present the kinds of statistical regularities that could teach the organizational principles of different kinds. We will study the statistical properties of a corpus of about 300 nouns that are typical of the first nouns that children learn. 2. The statistical regularities characteristic of early noun categories are sufficient to create knowledge about kinds. We will teach the corpus of nouns to an associative learning device, a connectionist net. 3. The specific nouns known by an individual child determine how that child interprets and generalizes a newly encountered noun. We will measure the individual nouns known by children 20 to 36 months of age and their generalization of novel nouns in an artificial word learning task. We will present the connectionist network with the nouns that individual children know and attempt to model individual children's performances in artificial word learning tasks. 4. Children learning different languages exhibit different developmental trajectories. We will test hypotheses 1 through 3 in two languages - English and Japanese. Past research indicates that English- and Japanese-speaking children differ in their interpretation and generalization of novel names for novel objects. This research tests the idea that this is because children's novel noun generalizations reflect the statistical properties of the nouns that they have already learned. Children become smart learners of the specific language they are learning.