This article reports results from a study investigating the impact of a sustained, comprehensive early algebra intervention in third grade. Participants included 106 students; 39 received the early algebra intervention, and 67 received their district's regularly planned mathematics instruction. We share and discuss students' responses to a written pre- and post-assessment that addressed their understanding of several big ideas in the area of early algebra, including mathematical equivalence and equations, generalizing arithmetic, and functional thinking. We found that the intervention group significantly outperformed the nonintervention group and was more apt by posttest to use algebraic strategies to solve problems. Given the multitude of studies among adolescents documenting students' difficulties with algebra and the serious consequences of these difficulties, an important contribution of this research is the finding that—provided the appropriate instruction—children are capable of engaging successfully with a broad and diverse set of big algebraic ideas.

Response styles are frequently of concern when rating scales are used in psychological survey instruments. While latent trait models provide an attractive way of controlling for response style effects (Morren, Gelissen, & Vermunt, 2011), the analyses are generally limited to accommodating only a small number of response style types. The use of anchoring vignettes provides an opportunity to overcome this limitation. In this article, a new latent trait model is introduced that uses vignette responses to measure and control for any form of response style. An illustration is provided with data from a cross-national study of self-reported conscientiousness by Mõttus, Allik, Realo, Pullman, et al. (2012).

Background-Five health-related quality-of-life (HRQoL) indexes-EQ-5D, HUI2, HUI3, QWB-SA, and SF-6D-are each used to assign community-based utility scores to health states, although these scores differ.

Pain sensitivity decreases with exercise. The mechanisms that underlie this exercise-induced hypoalgesia (EIH) are unclear. Our purpose was to investigate conditioned pain modulation (CPM) as a potential mechanism of EIH. Sixteen women completed pain testing during three sessions: painful exercise, nonpainful exercise, and quiet rest. Intensity and unpleasantness ratings to noxious heat stimuli were assessed at baseline and during and following each session. Results showed that pain sensitivity decreased significantly during both exercise sessions (p < .05), but not during quiet rest. Effect size calculations showed that the size of the hypoalgesic response was greater following painful exercise than nonpainful exercise. Our results suggest that exercise-induced muscle pain may contribute to the magnitude of EIH. However, as pain sensitivity also decreased following nonpainful exercise, CPM is not likely the primary mechanism of EIH.

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generalized method of moments, omitted variable bias, model specification test, robust estimation, consistency, empirical standard errors, hierarchical linear models,

hierarchical linear models, omitted effects, model specification test, fixed-effects estimators, random-effects estimators, Hausman test, unobserved heterogeneity,

No abstract