Understanding the Results of Multiple Linear Regression: Beyond Standardized Regression Coefficients

Multiple linear regression (MLR) remains a mainstay analysis in organizational research, yet intercorrelations between predictors (multicollinearity) undermine the interpretation of MLR weights in terms of predictor contributions to the criterion. Alternative indices include validity coefficients, structure coefficients, product measures, relative weights, all-possible-subsets regression, dominance weights, and commonality coefficients. This article reviews these indices, and uniquely, it offers freely available software that (a) computes and compares all of these indices with one another, (b) computes associated bootstrapped confidence intervals, and (c) does so for any number of predictors so long as the correlation matrix is positive definite. Other available software is limited in all of these respects. We invite researchers to use this software to increase their insights when applying MLR to a data set. Avenues for future research and application are discussed

Reliability generalization for the Motivated Strategies for Learning Questionnaire: A meta-analytic view of reliability estimates

A reliability generalization meta-analysis was performed to explore the relationship between study factors and levels of alpha reliability for the 15 subscales of the Motivated Strategies for Learning Questionnaire (MSLQ). The MSLQ has been widely adapted over the past 25 years to investigate the role of motivation and strategies in learning, primarily at the postsecondary level. A literature search from the years 1991 to 2015 yielded 295 peer-reviewed journal articles and 1,369 alpha reliability coefficients. Articles were coded for six potential moderator study variables. A novel varying coefficient (VC) model was adopted to determine average reliabilities across studies for each subscale and to perform multiple regression analyses to identify study variables that may moderate alpha reliability estimates. Commonality analyses were used to aid in interpretation of regression results. Meta-analyzed alpha reliabilities were lower than values published in the test manual for all but three of the subscales. Ability of specific moderators to predict score reliability varied across subscales; however, studies in North America, in English, or using a 7-point response scale generally corresponded to increased reliability estimates. Knowledge of expected levels of score reliability under varying sample and study conditions may provide useful information for researchers planning future use of the MSLQ

Defining traumatic events: An examination of the A criteria

https://nsuworks.nova.edu/cps_facbooks/1391/thumbnail.jp

Frequency Doubling Technology Perimetry and Changes in Quality of Life of Glaucoma Patients: A Longitudinal Study

PURPOSE: To evaluate the relationship between rates of change on frequency doubling technology (FDT) perimetry and longitudinal changes in quality of life (QoL) of glaucoma patients. DESIGN: Prospective observational cohort study. METHODS: One hundred fifty-two subjects (127 glaucoma and 25 healthy) followed for an average of 3.2 ± 1.1 years. All subjects were evaluated with National Eye Institute Visual Function Questionnaire (NEI VFQ-25), FDT and standard automated perimetry (SAP). Glaucoma patients had a median of 3 NEI VFQ-25, 8 FDT and 8 SAP tests during follow up. Mean sensitivities of the integrated binocular visual fields were estimated for FDT and SAP and used to calculate rates of change. A joint longitudinal multivariable mixed model was used to investigate the association between change in binocular mean sensitivities and change in NEI VFQ-25 Rasch-calibrated scores. RESULTS: There was a statistically significant correlation between change in binocular mean sensitivity for FDT and change in NEI VFQ-25 scores during follow-up in the glaucoma group. In multivariable analysis with the confounding factors, each 1dB/year change in binocular FDT mean sensitivity corresponded to a change of 0.8 units per year in the NEI VFQ-25 scores (P = 0.001). For binocular SAP mean sensitivity, each 1 dB/year change was associated with 2.4 units per year change in NEI VFQ-25 scores (P < 0.001). The multivariable model containing baseline and rate of change information from SAP had stronger ability to predict change in NEI VFQ-25 scores compared to the equivalent model for FDT (R(2) of 50% and 30%, respectively; P = 0.001). CONCLUSION: SAP performed significantly better than FDT in predicting change in NEI VFQ-25 scores in our population, suggesting that it may still be the preferable perimetric technique for predicting risk of disability from the disease

Predicting Individual Differences in Reading and Spelling Skill With Artificial Script–Based Letter–Speech Sound Training

In this study, we examined the learning of letter-speech sound correspondences within an artificial script and performed an experimental analysis of letter-speech sound learning among dyslexic and normal readers vis-à-vis phonological awareness, rapid automatized naming, reading, and spelling. Participants were provided with 20 min of training aimed at learning eight new basic letter-speech sound correspondences, followed by a short assessment of mastery of the correspondences and word-reading ability in this unfamiliar script. Our results demonstrated that brief training is moderately successful in differentiating dyslexic readers from normal readers in their ability to learn letter-speech sound correspondences. The normal readers outperformed the dyslexic readers for accuracy and speed on a letter-speech sound matching task, as well as on a word-reading task containing familiar words written in the artificial orthography. Importantly, the new artificial script-related measures were related to phonological awareness and rapid automatized naming and made a unique contribution in predicting individual differences in reading and spelling ability. Our results are consistent with the view that a fundamental letter-speech sound learning deficit is a key factor in dyslexia