Beliefs about whether or not children receive corrective input for grammatical errors depend crucially on how one defines the concept of correction. Arguably, previous conceptualizations do not provide a viable basis for empirical research (Gold, 1967; Brown & Hanlon, 1970; Hirsh-Pasek, Treiman & Schneiderman, 1984). Within the Contrast Theory of negative input, an alternative definition of negative evidence is offered, based on the idea that the unique discourse structure created in the juxtaposition of child error and adult correct form can reveal to the child the contrast, or conflict, between the two forms, and hence provide a basis for rejecting the erroneous form. A within-subjects experimental design was implemented for 36 children (mean age 5;0), in order to compare the immediate effects of negative evidence with those of positive input, on the acquisition of six novel irregular past tense forms. Children reproduced the correct irregular model more often, and persisted with fewer errors, following negative evidence rather than positive input.

Until recently, a long-standing assumption in the field of child language acquisition research was that parents do not correct the grammatical errors of their children. While consensus now exists that potentially corrective responses are often supplied, controversy persists as to whether the child can identify and exploit such information in practice. To address these issues, this study adopts the contrast theory of negative input as a framework for analysis (Saxton 1995). In this theory, two distinct kinds of corrective input are identified, termed negative evidence and negative feedback, respectively. The corrective potential of each category was investigated by examining the immediate effects of each on the grammaticality of child speech. A longitudinal corpus of naturalistic data (49 hours) from a single child was analysed with respect to 11 grammatical categories. The effects of negative input were compared with two non-corrective sources of input, namely positive input and adult move-ons. It was found that grammatical forms were more frequent in child speech following negative evidence and negative feedback than either of the two non corrective sources of input. In light of these and related findings, it is argued that corrective input may well prove important in explanations for how the child eventually retreats from error to attain a mature system of grammar.

No abstract

The relation between skill in simple addition and subtraction and more general math achievement in elementary school is well established but not understood. Both the intrinsic importance of skill in simple calculation for math and the influence of conceptual knowledge and cognitive factors (working memory, processing speed, oral language) on simple calculation and math are plausible. The authors investigated the development of basic calculation fluency and its relations to math achievement and other factors by tracking a group of 259 United Kingdom English children from second to third grade. In both grades the group did not retrieve the solutions to most problems, but their math achievement was typical. Improvement in basic calculation proficiency was partially predicted by conceptual knowledge and cognitive factors. These factors only partially mediated the relation between basic calculation and math achievement. The relation between reading and math was wholly mediated by number measures and cognitive factors.

There is growing evidence that corrective input for grammatical errors is widely available to children (Farrar, 1992; Morgan, Bonamo & Travis, 1995). However, controversy still exists concerning the extent to which children can identify and exploit available negative input. In particular, very little is yet known about the longer-term effects of negative input. Performing a time series analysis on observational data, Morgan et al. (1995) conclude that corrective recasts are not related to future improvements in grammaticality. It is argued here, though, that the data sets analysed in this study are inherently ill-suited to the demands of time series analyses. The present study adopts an experimental approach in order to compare the effects of negative evidence versus positive input on the acquisition of irregular past tense verb forms. Twenty-six children (mean age 3;10) participated in a within-subjects design over a period of five weeks. It was found that improvements in the grammaticality of child speech were considerably greater in cases where negative evidence had been provided. Moreover, children's intuitions concerning the status of irregular and overregularized forms more closely approximated adult intuitions when corrective input was available.