Similar phonological processes can be governed by different constraint
s. Davis (1995) claims that the effect of such process-specific constr
aints cannot be obtained in Optimality Theory (OT), exemplifying this
point with material from harmony in Palestinian Arabic. On the contrar
y, I show that process-specific constraints are a natural and expected
result of constraint ranking, the fundamental idea of OT. Furthermore
, OT makes a restrictive prediction, the subset criterion, about coexi
stent process-specific constraints within a single grammar-a predictio
n supported by the Palestinian material. Davis also presents evidence
that epenthetic segments have featural specifications, claiming that O
T says they are featureless. This is incorrect; OT is a model of const
raint interaction, not of the representation of epenthetic segments.