Comparing Models of Change to Estimate the Mediated Effect in the Pretest–Posttest Control Group Design

Models to assess mediation in the pretest–posttest control group design are understudied in the behavioral sciences even though it is the design of choice for evaluating experimental manipulations. The article provides analytical comparisons of the four most commonly used models to estimate the mediated effect in this design: analysis of covariance (ANCOVA), difference score, residualized change score, and cross-sectional model. Each of these models is fitted using a latent change score specification and a simulation study assessed bias, Type I error, power, and confidence interval coverage of the four models. All but the ANCOVA model make stringent assumptions about the stability and cross-lagged relations of the mediator and outcome that might not be plausible in real-world applications. When these assumptions do not hold, Type I error and statistical power results suggest that only the ANCOVA model has good performance. The four models are applied to an empirical example.     

PubMed Instruction for Medical Students: Searching for a Better Way

In 2007, Duke University Medical Center Library instituted an interactive, online PubMed tutorial and quiz for medical students to replace an in-person lecture. This article describes the events leading to this educational paradigm shift and how the tutorial was implemented. Important concerns in the switch to an online approach to PubMed training were student satisfaction and the extent to which searching skills would improve. To determine the effectiveness of the online model, two years of student quizzes and evaluations were examined. Results indicate that students benefit from and appreciate the interactive tutorial.     

Part 2. If We Frame It,They Will Respond: Student Responses to the Framework for Information Literacy for Higher Education

The second part of this exploratory study compares student pretest and posttest responses conducted at the beginning and end of a semester-long research methods course to measure the evolution of undergraduate students’ comprehension of information literacy concepts as presented in the Framework for Information Literacy for Higher Education’s Frames.