Lexical development assignment (1page due in a week) (revised, S2011)

Norms for lexical development may be accessed at the Macarthur-Bates communication inventories (CDI) website at:

http://www.sci.sdsu.edu/cdi/ or at the more complex site CLEX (soon?) to allow cross-language comparisons.


I have taken their data for the use of two verbs, think and throw and plotted it below. In blue you see the proportion of children using think' in pink you see the proportion of children using throw. For those wanting to see more acquisition data, take a look at CHILDES web site. This could be a great resource for a research paper.


Another site accesses CHILDES for frequency and MLU (mean length of utterance data). http://childfreq.sumsar.net/

Bååth, R. (2010). ChildFreq: An Online Tool to Explore Word Frequencies in Child Language. LUCS Minor, 16.

(available as pdf from above "sumsar" site.)

Note that these are two complementary approaches to estimating children's vocabulary, parental estimates (CDI) and actual word counts from transcribed utterances.


age beginning at 16 months through 30 months

1.What are some of the factors that might explain the differences in this pattern of acquisition? (There is no absolutely correct answer.)

2. Would you expect the pattern of acquisition to vary in children acquiring English as a second language-- presumably after requisite cognitive skills have been acquired? What would finding the same pattern of acquisition suggest about the whole process? Read Snedeker et al (2007) linked below for major clues!

3. One way word meanings may be acquired is through "syntactic bootstrapping." This is more or less (Gleitman, 1990) making a good guess based on the linguistic frame or context of the word. Here is a new word -- what do you think it might mean? Explain why you think so?

"Professor Limber is too chudle to play golf."

Note that Pinker (1994) uses "bootstrapping" in a somewhat different setting -- as a hypothsis on how children get a grip on grammatical categories using semantic notions, e.g. agents are subjects, actions are verbs...... semantic bootstrapping.

Gleitman, L. (1990) The structural source of verb meaning, Language Acquisition 1, 3-55. (There are many papers on this issue.)

For an interesting use of the CDI, see the Snedeker papers and projects.

Snedeker, J., Geren, J., & Shafto, C.L. (2007). Starting over: International adoption as a natural experiment in language development. Psychological Science, 18:79-87.