Focuses on the experimental designs and methodology of 15 studies, most of which used only part of the methodology for the experimental analysis of behavior. Argues that the failure to fully use available research technology may have contributed to researchers' failure to make experimental contact with the definition of reinforcement. (RH)

Proposes an interference explanation of data from dual-task studies of memory development. Dual-task data support the resources hypothesis that memory processes tax a common pool of cognitive energy, which has been variously called attentional, mental effort, and working-memory capacities. Suggests that dual-task deficits are instances of output…

This response to Brainerd and Reyna's paper (in this issue) argues that the common resources hypothesis can be applied to a wider range of phenomena than can the output-interference hypothesis. Presents results of a dual-task experiment under bidirectional deficits. Concludes that dual-task studies do not provide critical tests of the resources…

This response to Brainerd and Reyna's paper (in this issue), questions whether output-interference and resource theories can readily be differentiated empirically. Argues that dual-task studies, while important, do not serve as the critical tests of the resources hypothesis. (RH)

Argues that dual-task performance is currently not interpretable because several compatible hypotheses have been offered to account for dual-task interference. Demonstrates inability to discriminate among alternative hypotheses by constructing a model which includes limited resources and response competition and requires running at least eight…

Argues that the resources and response competition models discussed by Brainerd and Reyna (in this issue) may not be mutually exclusive, but instead may model different aspects of performance. The problem is not to decide between the two models in general, but rather to determine which aspects of performance are best explained by each. (RH)

Reyna and Brainerd supplement arguments they made previously in this issue by advancing five additional reasons for preferring output-interference explanations over the resources hypothesis. (RH)

Three studies examined the hypotheses that: (1) codability and not extent of distance determines difficulty; (2) critical features and not whole objects are coded; and (3) implicit perceptual axes provide a frame of reference for coding the display. Results supporting these hypotheses are discussed in terms of a description of spatial…

Explored mechanisms responsible for improvements in short-term memory in early to middle childhood. Recall and speech rate for acoustically similar and dissimilar words and words of differing lengths were assessed in three groups of children of 4 to 10 years. (RH)

Among 294 children of three to eight years, tactual oddity learning increased gradually with age. The finding of bidirectional cross-modal transfer of oddity learning supported the suggestion that such transfer occurs when training and transfer oddity tasks share a common vehicle dimension. Results are considered consistent with the view that…

Findings of two experiments support the contention that children and adults are capable of using both hypothetical counter-exemplar reasoning and functionality to make definitional category judgments. Results are discussed in terms of Richards and Goldfarb's (1986) model of episodic memory and are related to other evidence that children possess…

Results of two studies investigating preschool children's ability to infer another person's knowledge or ignorance on the basis of that person's recent perceptual experience suggest that understanding of perception as a source of knowledge is present by the age of three years. (RH)

Data suggest that human newborns are capable of making a chromatic discrimination within the spectral region above 540 nm (the Rayleigh region), but their ability is limited to chromatic stimuli of very wide spectral separation and of very large size. Possible neurological bases underlying this immaturity are discussed. (RH)

Two experiments suggest that the empirical finding of age differences in automatic frequency processing depends on the extent to which subjects can or do strategically process task materials in a differential fashion. This interpretation is considered compatible with a modified conception of automatic encoding which views such encoding processes…

Children between the ages of three and six years were asked to predict their success or failure in two tasks, each of which had five difficulty levels. Tasks were presented either simultaneously or successively. Results indicated that children made realistic assessments of their chances for success at the difficulty levels. Performance factors are…