The past several decades have seen numerous approaches toward automated diagnosis and instructional support of students engaged in mathematics problem-solving. These approaches typically involve detailed analysis of potential solution paths for problems, formal representations of correct and incorrect answers, and support in the form of feedback…

Background: A number of previous studies have revealed that children with Specific Language Impairment have limitations in Phonological Working Memory as revealed by a task that requires them to repeat non-words of increasing syllable length. However, most published studies have used non-words that are phonotactically English. Aims: The purpose…

The acquisition of noun gender on articles was studied in a sample of 21 young German-speaking children. Longitudinal spontaneous speech data were used. Data analysis is based on 22 two-hourly speech samples per child from 6 children between 1 ; 4 and 3 ; 8 and on 5 two-hourly speech samples per child from 15 children between 1 ; 4 and 2 ; 10. The…

Business professionals and instructors often view writing skills as one of the most important qualifications that employees should possess. However, many business employees, including recent college graduates, have serious writing deficiencies, especially in their ability to use standard English. As a result, American businesses spend billions of…

This paper studies the reliability and validity of naturalistic speech errors as a tool for language production research. Possible biases when collecting naturalistic speech errors are identified and specific predictions derived. These patterns are then contrasted with published reports from Germanic languages (English, German and Dutch) and one…

This article describes pedagogic issues in setting objective tests in mechanics using Question Mark Perception, coupled with MathML mathematics mark-up and the Scalable Vector Graphics (SVG) syntax for producing diagrams. The content of the questions (for a range of question types such as multi-choice, numerical input and variants such as…

The goals of this article are twofold: (a) briefly highlight the merits of residual centering for representing interaction and powered terms in standard regression contexts (e.g., Lance, 1988), and (b) extend the residual centering procedure to represent latent variable interactions. The proposed method for representing latent variable…

For two random variables, X and Y, let D = X - Y, and let theta[subscript x], theta[subscript y], and theta[subscript d] be the corresponding medians. It is known that the Wilcoxon-Mann-Whitney test and its modern extensions do not test H[subscript o] : theta[subscript x] = theta[subscript y], but rather, they test H[subscript o] : theta[subscript…

In a previous study (Dronkers, 1996), stroke patients identified as having apraxia of speech (AOS), an articulatory disorder, were found to have damage to the left superior precentral gyrus of the insula (SPGI). The present study sought (1) to characterize the performance of patients with AOS on a classic motor speech evaluation, and (2) to…

This article describes the case of a client who displayed some interesting patterns of realization of the target English phoneme /r/. These varied according to both distribution within the word, and style of utterance. We speculate as to the cause of some of these forms, and on possible therapy strategies.

Complex working memory span tasks have been shown to predict performance on a number of measures of higher-order cognition including fluid abilities. However, exactly why performance on these tasks is related to higher-order cognition is still not known. The present study examined the patterns of errors made on two common complex span tasks. The…

Moving visual stimuli have been shown to reduce unilateral neglect (ULN), however, the mechanisms underlying these effects remain poorly understood. This study compared lateralised and non-lateralised moving visual stimuli to investigate whether the spatial characteristics or general alerting properties of moving visual stimuli are responsible for…

Several hypotheses related to Newman's (e.g., Patterson & Newman, 1993) response modulation hypothesis were examined among adolescents with attention-deficit/hyperactivity disorder (ADHD; n = 18) and normal controls (n = 23). Consistent with predictions, youth with ADHD committed more passive avoidance errors (PAEs) than controls during the latter…

The purpose of this study was to examine the linkages among selective attention, memory bias, cognitive errors, and anxiety problems by testing a model of the interrelations among these cognitive variables and childhood anxiety disorder symptoms. A community sample of 81 youth (38 females and 43 males) aged 9-17 years and their parents completed…

The standard univariate and multivariate methods are conventionally used to analyze continuous data from groups by trials repeated measures designs, in spite of being extremely sensitive to departures from the multisample sphericity assumption when group sizes are unequal. However, in the last 10 years several authors have offered alternative…