A comparison of Merge, a model of comprehension, and WEAVER, a model of pro
duction, raises five issues: (1) merging models of comprehension and produc
tion necessarily creates feedback; (2) neither model is a comprehensive acc
ount of word processing; (3) the models are incomplete in different ways; (
4) the models differ in their handling of competition: (5) as opposed to WE
AVER, Merge is a model of metalinguistic behavior.