1. Information Provided in Adult- Child Discourse about the Meaning of Adjectives Roberta Corrigan University of Wisconsin- Milwaukee

2. Abstract Adult English-language discourse from the CHILDES corpus was examined for the types of information provided to children about the meaning of “rare” adjectives (those occurring less than 5 times in 2.6 million words). The discourse context in which the word was spoken was examined for the types of information that it provided to the meaning of the adjective. Results support the view that adult discourse to children provides informative data for the lexical acquisition process.

3. The CHILDES system provides tools for studying conversational interactions. These tools include a database of transcripts, programs for computer analysis of transcripts, methods for linguistic coding, and systems for linking transcripts to digitized audio and video. CHILDES Child Language Data Exchange System http://childes.psy.cmuhttp://childes.psy.cmu. edu/

4. Preparing the “Rare” Adjective List Begin with Childes Parental Corpus of ~24,000 word types Select types occurring with frequency of ≤ 5 per 2.6 million tokens Remove non-words Find words that are “rare” in English =do not occur in the 10,000 most common English words

5. Preparing the “Rare” Adjective List (continued) Eliminate obvious nouns, verbs and adverbs from the list. List of potential adjectives contained ~1330 words. Check context of remaining words (± 3 utterances on either side of target) to determine word class. Final word list contains 944 adjectives

6. Characteristics of Conversational Partners Age Range Total NumberNumber of “Rare Adjective” Addressees Proportion “Rare Adjective” Addressees up to 2.542673.17 2.5 to 4 years 36776.21 > 4 years429105.25 Adult526168.32

7. Relative Frequency of Rare Word Types Produced to Different Ages

8. Categories of Information Provided in Surrounding Text

9. Categories of Information (continued)

11. Percentage of Contexts Providing at Least One Contextual Clue to Meaning χ 2 (1) =18.50, p <.0001

12. Percent Explicit Definitions in Child-Directed vs. Adult- Directed Speech χ 2 (3) = 16.83, p <.001

13. Percent Evaluative Information in Child-Directed vs. Adult Directed Speech χ 2 (3) = 12.72, p <.005

14. Percent Contrastive Information in Child-Directed vs. Adult Directed Speech χ 2 (3) = 5.24, p >.05

15. Discussion/Conclusions This paper compared child-directed to adult-directed adjectives that were likely to be unfamiliar to children. The use of “rare” lexical items is a promising technique for examining adult input for lexical acquisition in corpus data where the child’s vocabulary is unknown. Results suggest that adult discourse to children provides data for the lexical acquisition process. Adults provide more information about adjective meanings to their young conversational partners than they do to other adults.

16. Not all information categories are equally informative for all ages. The findings highlight the importance of looking at adult input in situations where teaching the meaning of adjectives is not an explicit goal.