Two Observations of E. Bates

[Steve Pinker]

(1) Concerning the development of the past tense, Elizabeth Bates
writes "there is no U-shaped function", based on Marchman's data.
This implies that researchers in the area have made some
fundamental error that vitiates their attempts at theory.  

But, as noted in our comments on Marchman, the 'U'-sequence that
everyone refers to is simply that (i) very young children do not
overregularize from the day they begin to talk, but can use some
correct past tense forms (e.g. 'came') for a while before (ii)
overregularizations (e.g. 'comed') appear in their speech, which (iii)
diminish by adulthood. Thus if you plot percentage of
overregularizations against time, the curve is nonmonotonic in a way
that can be described as an inverted-U.  This is all that we (or
everyone else) mean by 'stages' or 'U-shaped development', no more, no
less. No one claims that the transitions are discrete, or that the
behavior within the stages is simple or homogeneous (this should be
clear to anyone reading R&M or OLC).  Marchman herself does not
present any data that contradict this familiar characterization.  Nor
could she; her study is completely confined to children within stage
(ii).

Further discussion of the relation between Marchman's data and
the empirical picture drawn in R-M, OLC and other studies can be
found in our remarks on Marchman. 

(2) Bates runs two issues together: 
     -whether judgments are always "crisp" 
               ('sneaked' versus 'snuck'), 
     -whether verbs derived from nouns and adjectives are regular
          ('out-Sally-Rided' versus 'overrode'). 

The implication is that endemic sogginess of judgment, overlooked or
suppressed by linguists, makes it impossible to say anything about
regularization-through-derivation.

Noncrispness of judgments of irregular forms was confronted explicitly
in OLC, which has a pretty thorough documentation of the phenomenon
(p. 116-117, p. 118-119, and the entire Appendix).

The important thing about the the cross-category effect is that it
implies that the linguistic notions 'irregular', 'root', and
'syntactic category' have mentally-represented counterparts; it also
emerges from a conspicuously narrow exposure to the data (since
learners are not flooded with examples of denominal verbs that happen
to be homophonous with irregulars); it is found with consistency
across languages.

The effect could be true whether the judgments respect part-of-speech
distinctions absolutely or probabilistically.  As long as a
significant proportion of the variance is uniquely accounted for by
syntactic category, there is something to explain.

In fact, of course, most of the relevant judgments are quite clear
(*high-stuck the goalie, *kung the checkers piece; OLC p. 111), and
there can be little question that syntactic category is a compelling
force for regularization, far more potent that unaided semantics (e.g.
'he cut/*cutted a deal'; OLC pp. 112-113). We regard this effect (due
largely to work by Kiparsky) as a major, surprising discovery about
the way linguistic systems are organized.  For specific hypotheses
about *when* and *why* some such judgments should be fuzzy, see Note
17 (p. 112) and pp.  126-127.

Alan Prince
Steven Pinker