more thoughts on MLU

[Ann Peters]

I would like to add some thoughts following on from Ginny's.
A basic issue for me has been: how many *separate pieces* of language can
a particular child assemble at a given time? Asking such a question would
lead me to count both 'fall' and 'fell' as single units. It would further
lead me to ask whether an expression such as 'pi(ck)-ya-up' always
occurred as an unanalyzed unit (in which case I would count it as one) or
if it contrasted with 'pick it/them up' etc. Similarly I would count the
German article 'die' as one, unless I were directly dealing with issues of
contrast in number, case, and/or gender. The down side of such an approach
is that one can't make an automatic count of a child's MLU, since it
requires knowing which collocations are productive for a particular child.
Of course, one can ask other kinds of questions, such as: how many
contrastive *meanings* can a child encode into a sentence? in which case
one might need different rules for counting. This suggests that there is
not one single "MLU" measure that suffices for all purposes. One problem I
have been struggling with is how to count "filler syllables", that seem to
be separate "units" in a phonological sense, but don't carry much (if
anything) in the way of meaning. I find that I want more than one count -
at a minimum MLU in open-class "words", MLU in number of identifiable
morphemes, and a measure that counts fillers as well.
A final cross-linguistic thought: even if one took a construction grammar
approach, it might turn out that the number of "meaningful units" that a
child could *combine* might be more or less equatable across languages,
and that "stages" could be computable in that way.
ann


****************************
Dr. Ann M. Peters, Professor Emeritus
Graduate Chair                      http://www.ling.hawaii.edu/
Department of Linguistics
University of Hawai`i               email: ann at hawaii.edu
1890 East West Road, Rm 569         phone: 808 956-3241
Honolulu, HI  96822                 fax:   808 956-9166
http://www.ling.hawaii.edu/faculty/ann/