This report on research in progress explores criteria for lexical innovation in children. Children, like adults, make use of a principle of conventionality (each word has one or more conventional meanings) and one of contrast (the conventional meanings of every two words contrast). Like adults, children coin words to fill lexical gaps, and they do so according to certain principles that are reflected by apparent strategies: (1) one-to-one matches of meaning and form are easier to acquire than one-many or many-one matches ("Look for word-formation devices that are words in their own right and use those in constructing new words."); (2) simpler forms are easier to acquire than more complex ones, where simplicity is measured by degree of change in form ("Make as few changes as possible in forming a new word from an old one."); (3) the paradigms of a language are regular in form ("Use the same word-formation device everywhere to mark the same meaning in forming new words."); and (4) the most creative adult word-formation devices are the most productive, and the most available to children ("Look for the commonest device that expresses the desired meaning and use that in constructing a new word-form." (JB)