The contrastive hierarchy in phonology 2009 Dresher.pdf - CUNY ...

ules to which a purely formal evaluation measure would assign incorrect
relative costs. 1
(5.1) Pairs of rules (Chomsky and Halle 1968: 401)
a. i. i u ii. i ˆ
b. i. t s ii. t T
c. i. k tS /_____ ii. tS k/_____
In (5.1a), rule (i) is formally more complex than (ii) because it changes an extra
feature, [round], in addition to a change in [back]: i is [–back, –round], among
other features not in play here, ˆ is [+back, –round], and u is [+back, +round].
Nevertheless, rule (i) is much more common than rule (ii). This is presumably
because [u] is a more common segment than [ˆ], a fact not recognized by the SPE
theory, which only counts the number of symbols in a rule, and does not
evaluate their content. In this case the cost of the extra feature in rule (i) is
outweighed by the more natural result. Or, rather, the cost of the extra feature is
only apparent.
The case of (5.1b) is similar. Of the features relevant to this rule, t is
[–continuant, –strident], T is [+continuant, –strident], and s is [+continuant,
+strident]. Rule (5.1bii) appears to be the cheaper rule because it changes only
[continuant], in the SPE feature system, whereas rule (i) also changes [strident].
Again, the formally simpler rule is less common than the more complex one,
because [s] is a more common segment than [T].
€
⎡ – cons⎤
⎣ ⎢ – back⎦
⎥
1 In this chapter I have modified the phonetic symbols in the sources to reflect IPA values.
€
⎡ – cons⎤
⎣ ⎢ + back⎦
⎥
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