Individual differences in response to treatments have been a long-standing interest in education, psychology, and related fields. This article presents a conceptual framework and hierarchical modeling strategies that may help identify the subgroups for whom, or the conditions under which, a particular treatment is associated with better outcomes.…

Does the choice of test for assessing reading comprehension influence the outcome of genetic analyses? A twin design compared two types of reading comprehension tests classified as primarily associated with word decoding (RC-D) or listening comprehension (RC-LC). For both types of tests, the overall genetic influence is high and nearly identical.…

This study explored the prevalence of violent behaviors in patients who are addicted to drugs. A sample of 252 addicted patients (203 male and 49 female) who sought outpatient treatment was assessed. Information on violent behaviors, sociodemographic factors, consumption factors (assessed by the European version of the Addiction Severity Index…

Improving reading rate can be difficult for poor readers. In this experiment, we investigated the impact of improvement in reading rate on other aspects of reading, including word recognition, decoding, vocabulary, and comprehension. Poor readers in Grades 2 or 4 (N = 123) were randomly assigned to 1 of 3 conditions: practice reading text at their…

Previous studies provide empirical support for the reported colour experience in grapheme-colour synaesthesia by measuring the synaesthetic experience from an externally presented grapheme. The current study explored the synaesthetic experience resulting from a visual mental image of a grapheme. Grapheme-colour synaesthetes (N=6) and matched…

One of the most consistent findings in children with ADHD is increased moment-to-moment variability in reaction time (RT). The source of increased RT variability can be examined using ex-Gaussian analyses that divide variability into normal and exponential components and Fast Fourier transform (FFT) that allow for detailed examination of the…

Sentences with non-canonical wh- movement are often difficult for individuals with agrammatic Broca's aphasia to understand (Carramazza & Zurif, 1976, inter alia). However, the explanation of this difficulty remains controversial, and little is known about how individuals with aphasia try to understand such sentences in real time. This study uses…

This article describes how effectively multimedia learning environments can assist second language (L2) students of different spatial and verbal abilities with listening comprehension and vocabulary learning. In particular, it explores how written and pictorial annotations interacted with high/low spatial and verbal ability learners and thus…

The difference in effect on power of restriction of range between treatments under experimental control and categories formed from examinee (individual differences) variables is discussed. Conditions under which there is loss or increase of power are explained. (SLD)

Evoked potential studies have demonstrated that musicians have the ability to distinguish musical sounds preattentively and automatically at the temporal, spectral, and spatial levels in more detail. It is however not known whether there is a difference in the early processes of auditory data processing of musicians. The most emphasized and…

Individual differences in response to a given treatment have been a longstanding interest in education. While many evaluation studies focus on average treatment effects (i.e., the effects of treatments on the levels of outcomes of interest), this paper additionally considers estimating the effects of treatments on the dispersion in outcomes.…

The present study examines the effect of participation of first-year university students in a full-year peer mentoring program as well as individual differences in motivation in relation to outcome measures of retention and achievement. A sample of 983 first year students completed the Academic Motivation Inventory (Tremblay, 1998) and agreed to…