Children may be able to gain partial information about the meaning of a word from clues, such as how it is used in a sentence and what words it is contrasted with. This strategy, known as "fast mapping," may provide a very useful first step in language learning. One question which arises from studies of fast mapping is whether fast mapping is available to children across various semantic domains, such as shape, texture, and color. A total of 50 children (with a mean age of 3 years, 8 months) participated in the first study, and 33 children (with a mean age of 2 years, 9 months) participated in the second. Children were introduced to a novel color, shape, or texture term by contrasting the new term with a well-known word from that domain. They were then tested for both their ability to produce and comprehend the new term and whether they knew the semantic domain the word referred to. The data show that children can gain some information about the meaning of a word from a brief encounter. In contrast to rather slow and difficult hypothesis-testing mechanisms, fast mapping may allow the child to rapidly obtain information from the situation. By considering only a few hypotheses, the child can then quickly focus in on the correct meaning. (Author/RH)