Some thoughts on Snedeker & Huang 2016 in press

One of the things I really enjoyed about this book chapter was all the connections I can see for language acquisition modeling. An example of this for me was the discussion about kids’ (lack of) ability to incorporate pragmatic information of various kinds (more detailed comments on this below). Given that some of us in the lab are currently thinking about using the Rational Speech Act model to investigate quantifier scope interpretations in children, the fact that four- and five-year-olds have certain pragmatic deficits is very relevant. 

More generally, the idea that children’s representation of the input — which depends on their processing abilities — matters is exactly right (e.g., see my favorite Lidz & Gagliardi 2015 ref). As acquisition modelers, this is why we need to care about processing. Passives may be present in the input (for example) but that doesn’t mean children recognize them (and the associated morphology). That is, access to the information of the input has an impact, beyond the reliability of the information in the input, and access to the information is what children’s processing deals with.

More specific thoughts:

18.1:  I thought it was interesting that there are some theories of adult sentence processing that actively invoke an approximation of the ideal observer as a reasonable model (ex: the McRae & Matuski 2013 that SH2016 cite). I suppose this is the foundation of the Rational Speech Act model as well, even though it doesn’t explicitly consider processing as an active process per se.

18.3: Something that generally comes out of this chapter is children’s poorer cognitive control (which is why they perseverate on their first choices). This seems like it could matter a lot in pragmatic contexts where children’s expectations might be violated in some way. They may show show non-adult behavior not because they can’t get the correct answer, but rather that they can’t get to the correct answer once they’ve built up a strong enough expectation for a different answer.

18.4: Here we see evidence that five-year-olds aren’t sensitive to the referential context when it comes to disambiguating an ambiguous PP attachment (as in “Put the frog on the napkin in the box”). (And this contrasts with their sensitivity to prosody.) So, not only do they perseverate on their first mistaken interpretation, but they apparently don’t utilize the pragmatic context information that would enable them to get the correct interpretation to begin with (i.e. there are two frogs so saying “the frog” is weird until you know which frog —  therefore “the frog on the napkin” as a unit makes sense in this communicative context). This insensitivity to the pragmatics of “the” makes me wonder how sensitive children are in general to pragmatic inferences that hinge on specific lexical items — we see in section 18.5 that they’re generally not good at scalar implicatures till later, but I think they can get ad-hoc implicatures that aren’t lexically based (Stiller et al. 2015). 

So, if we’re trying to incorporate this kind of pragmatic processing limitation into a model of child’s language understanding (e.g., cripple an adult RSA model appropriately), we may want to pay attention to what the pragmatic inference hinges on. That is, is it word-based or not? And which word is it? Apparently, children are okay if you use “the big glass” when there are two glasses present (Huang & Snedeker 2013). So it’s not just about “the” and referential uniqueness. It’s about “the” with specific linguistic ways of determining referential uniqueness, e.g., with PP attachment. HS2016 mention cue reliability in children’s input as one mitigating factor, with the idea that more reliable cues are what children pick first — and then they presumably perseverate on the results of what those reliable cues tell them.

18.6: It was very cool to see evidence of the abstract category of Verb coming from children’s syntactic priming studies. At least by three (according to the Thothathiri & Snedeker 2008 study), the abstract priming effects are just as strong as the within-verb priming effects, which suggests category knowledge that’s transferring from one individual verb to another. To be fair, I’m not entirely sure when the verb-island hypothesis folks expect the category Verb to emerge (they just don’t expect it to be there initially). But by three is already relatively early.

18.7: Again, something that comes to mind for me as an acquisition modeler is how to use the information here to build better models. In particular, if we’re thinking about causes of non-adult behavior in older children, we should look at the top-down information sources children might need to integrate into their interpretations. Children's access to this information may be less than adults have (or simply children's ability to utilize it, which may effectively work out to the same thing in a model).

References

Lidz, J., & Gagliardi, A. (2015). How nature meets nurture: Universal grammar and statistical learning. Annu. Rev. Linguist., 1(1), 333-353.

McRae, K., & Matsuki, K. (2013). Constraint-based models of sentence processing. In R. Van Gompel (Ed.), Sentence Processing (pp. 51-77). New York, NY: Psychology Press. 

Stiller, A. J., Goodman, N. D., & Frank, M. C. (2015). Ad-hoc implicature in preschool children. Language Learning and Development, 11(2), 176-190.