Research studies on sensory issues in autism, including those based on questionnaires, autobiographical accounts, retrospective video observations and early experimental approaches are reviewed in terms of their strengths and limitations. We present a cognitive neuroscience theoretical perspective on multisensory integration and propose that this…

Advocates of the ''continuity hypothesis'' have argued that innate non-verbal counting principles guide the acquisition of the verbal count list (Gelman & Gallistel, 1978). Some studies have supported this hypothesis, but others have suggested that the counting principles must be constructed anew by each child. Defenders of the continuity…

Consider the nonparametric regression model Y = m(X)+ [tau](X)[epsilon], where X and [epsilon] are independent random variables, [epsilon] has a median of zero and variance [sigma][squared], [tau] is some unknown function used to model heteroscedasticity, and m(X) is an unknown function reflecting some conditional measure of location associated…

Statistical terms are accurate and powerful but can sometimes lead to misleading impressions among beginning students. Discrepancies between the popular and statistical meanings of "conditional" are discussed, and suggestions are made for the use of different vocabulary when teaching beginners in applied introductory courses.

Two experiments were conducted to test the hypothesis that toddlers have access to an analog-magnitude number representation that supports numerical reasoning about relatively large numbers. Three-year-olds were presented with subtraction problems in which initial set size and proportions subtracted were systematically varied. Two sets of cookies…

This paper briefly describes unplanned and planned methods of evaluating differences between means and explains orthogonal versus nonorthogonal contrasts to help the researcher understand a framework of planned comparisons. A small heuristic data set is generated to illustrate the superiority of planned comparisons over omnibus analysis of…

Factorial analyses differ from nonfactorial analyses in that in the former all possible hypotheses (all possible main effects and interaction effects) are tested regardless of their substantive interest to the researcher and their interpretability, while in the latter, only substantive and interpretable hypotheses are tested. This paper shows the…

Controversy over the merits of Null Hypothesis Statistical Significance Testing (NHST) as a tool for advancing knowledge in the social sciences has intensified in recent years. Literature for and against the use of statistical significant tests is reviewed and three major limitations of these tests are summarized. The first is that "p"…

A description of the aptitude-treatment interaction concept is followed by some examples of ATI studies. (Author/HB)

Procedures developed by Joreskog for studying similarities and differences in factor structures between different groups were applied to data from a study by Thurstoen to investigate the sampling stability of a hypothesized isolated configuration. The hypothesis of an isolated configuration was rejected but not by much. (Author/RC)

In his early exposition of path analysis, Duncan (1966) noted that the method "provides a calculus for indirect effects." Despite the interest in indirect causal effects, most users treat them as if they are population parameters and do not test whether they are statistically significant. Sobel (1982) has recently derived the asymptotic…

In a previous study (Watson, 1960), college students were told that a three-number string ("2, 4, 6") conformed to a rule and that they had to guess the rule by proposing other three-number strings; they were then told whether each guess was right or wrong. However, it was suspected that, since the subject's hypothesis was falsified by…