If the basic operations hypothesis (EJ 184 227) is interpreted as a general principle governing acquisition of all movement rules, it may obscure the fact that children distinguish between unbounded and local rules. Error patterns support this distinction, lending credence to theories with separate status for the two rule types. (Author/RD)

Goodluck and Solan (EJ 205 641) presented alternative formulations about why errors predicted by basic operations fail to occur and suggested a refined hypothesis. Each aspect of their argument is addressed, and it is concluded that descriptive power, methodology and principles for restricting error predictions favor our original analysis. (RD)