Monday, June 16, 2008

Optimality Theory

The question: why does Ben Barnes (who plays Prince Caspian in the new Chronicles of Narnia movie) fail to aspirate the /k/ in Prince Caspian?
The answer: He ranks MOP above Align-Morph-R.

Don't worry, all will be explained. This will be the first of several posts dealing with the most recent theory in phonology: Optimality Theory, or OT for short. The idea behind OT is a simple and universal one, based on constraints. We all are familiar with constraints from our everyday lives. Would you rather spend that $20 on a movie or dinner? That's exactly what OT does for linguistics, except instead of figuring out how to spend money it's trying to figure out (in phonological applications) what the surface realization of an underlying form will be.

OT presents constraints as realizations such as Onset (which states that syllables should have onsets) and *Comp (which states that syllable margins should be simple, e.g., "string" would violate this because of the complex "str" cluster at the beginning). The problem, of course, is that we can't get everything we want all the time. If you only have $20, you can't spend $20 on dinner and then $20 on a movie. You have to pick one. Here's an example from OT.

One constraint is the Maximal Onset Principle, or MOP (it's questionable whether this is a necessary constraint; most likely NoCoda and S(onority)S(equencing) render it irrelevant in all cases, but we won't deal with that now). This states that if there's a question whether to assign a segment to the coda of the preceding syllable or the onset of the following syllable, you should do the latter. In the word "instance," we could syllabify it as ins.tance or in.stance, and MOP says we should pick the latter. Another common constraint is Align-X, where X can be L for left or R for right. It states (in the most vague definition possible) that things should be aligned with other things. This can apply at any level of abstraction. We are most concerned with Align-Morph-R, which I will define as "The right edge of a morpheme should be at the right edge of a syllable."

In the example I gave at the beginning of the post, these are the two relevant constraints. So, why do I aspirate the /k/ in Caspian while Ben Barnes doesn't? The MOP constraint wants us to assign as many segments as possible to the onset of the second syllable of Prince Caspian: prin.skaspian (clearly I'm not using IPA, I'm not going to venture into Unicode yet; that's for later this week). However, the morphemes are [prins] and [kaspian], so this syllabification violates Align-Morph-R, because the right edge of the morpheme [prins] in the onset of the following syllable. If we syllabify the phrase as prins.kaspian (I'm ignoring syllable boundaries in Caspian), we're violating MOP, because "sk" is a perfectly valid onset in English (school, escape, etc.). We can't fulfill both constraints, so we have to choose one. I choose [prins.][], because for me Align-Morph-R is ranked higher than MOP, i.e., I would rather have my morphemes lined up with syllable boundaries than assign as many segments as possible to onsets. Ben Barnes is the opposite; MOP is very important to him, so he chooses to violate Align-Morph-R: [prin.s][].

1 comment:

Alex said...

Also, Ben Barnes is new.