MplusAutomation: An R Package for Facilitating Large-Scale Latent Variable Analyses in Mplus

MplusAutomation is a package for R that facilitates complex latent variable analyses in Mplus involving comparisons among many models and parameters. More specifically, MplusAutomation provides tools to accomplish 3 objectives: to create and manage Mplus syntax for groups of related models; to automate the estimation of many models; and to extract, aggregate, and compare fit statistics, parameter estimates, and ancillary model outputs. We provide an introduction to the package using applied examples including a large-scale simulation study. By reducing the effort required for large-scale studies, a broad goal of MplusAutomation is to support methodological developments in structural equation modeling using Mplus.     

A study of race and gender bias in the punishment of handicapped school children

There is scant research concerned about punishment of handicapped, minority students in public schools. The purpose of this study was to investigate race and gender, types of rules violations, types of punishments, referral rates, referral frequencies, and follow-up activities to determine differences in treatment by race, sex, and handicapping condition. The sample consisted of 4,391 discipline files representing records from 9 schools in a district (K-12). All data were analyzed using the Chi Square statistic. It was demonstrated that racial bias existed in the administration of punishment, and that Black, male handicapped students were punished more severely than others for commission of the same offenses.     

Open-field behavior of wild and domestic Norway rats

The open-field behavior of wild and domestic Norway rats was compared in 15-min tests administered over 5 successive days. Wild rats exhibited more ambulation, jumping, grooming, and time inactive than domestic rats and spent more time along the arena wall. Within- and between-trial changes in behavior were generally greater for wild rats. Factor analyses revealed major loadings on factors identified as “locomotor behavior” and “grooming.” Support was obtained for the hypothesis that domestication has raised the threshold for avoidance-escape behavior in response to a novel environment.     

Social working memory: Memory for another rat's spatial choices can increase or decrease choice tendencies

In two experiments using a radial-arm maze, pairs of rats made choices among eight maze locations, each containing a large quantity of one of two food types. The choices made by 1 rat affected the choices made by the other rat. Under most conditions, visits by 1 rat increased the tendency of the other rat to subsequently choose that maze location. However, the effect depended on the quality of the food available in a particular location. When it was possible for the rats to observe each other on the maze arms and a rat had experienced that a location contained the less preferred food type, a previous visit to that location by the foraging partner decreased the tendency to visit that location. These effects are attributed to working memory for the spatial choices of another rat, and they indicate that memory produced by a rat’s own visit to a maze location is integrated with memory for the behavior of another rat to determine spatial choice     

Designing a college web-based course using a modified personalized system of instruction (PSI) model

Conclusion With proper planning and attention to instructional design, Web-based courses can provide a convenient and instructionally sound method of course delivery. The PSI model is a proven model that can be applied to many Webbased courses     

Social Pragmatics: Preschoolers Rely on Commonsense Psychology to Resolve Referential Underspecification

Four experiments show that 4- and 5-year-olds (total N = 112) can identify the referent of underdetermined utterances through their Naïve Utility Calculus—an intuitive theory of people’s behavior structured around an assumption that agents maximize utilities. In Experiments 1–2, a puppet asked for help without specifying to whom she was talking (“Can you help me?”). In Experiments 3–4, a puppet asked the child to pass an object without specifying what she wanted (“Can you pass me that one?”). Children’s responses suggest that they considered cost trade-offs between the members in the interaction. These findings add to a body of work showing that reference resolution is informed by commonsense psychology from early in childhood.     

The Spectrum of Learning and Teaching: The Impact of a Fourth-Year Anatomy Course on Medical Student Knowledge and Confidence

There is growing demand from accrediting agencies for improved basic science integration into fourth-year medical curricula and inculcation of medical students with teaching skills. The objective of this study was to determine the effectiveness of a fourth-year medical school elective course focused on teaching gross anatomy on anatomical knowledge and teaching confidence. Fourth-year medical student “teacher” participants' gross anatomy knowledge was assessed before and after the course. Students rated their overall perceived anatomy knowledge and teaching skills on a scale from 0 (worst) to 10 (best), and responded to specific knowledge and teaching confidence items using a similar scale. First-year students were surveyed to evaluate the effectiveness of the fourth-year student teaching on their learning. Thirty-two students completed the course. The mean anatomy knowledge pretest score and posttest scores were 43.2 (±22.1) and 74.1 (±18.4), respectively (P < 0.001). The mean perceived anatomy knowledge ratings before and after the course were 6.19 (±1.84) and 7.84 (±1.30), respectively (P < 0.0001) and mean perceived teaching skills ratings before and after the course were 7.94 (±1.24) and 8.53 (±0.95), respectively (P = 0.002). Student feedback highlighted five themes which impacted fourth-year teaching assistant effectiveness, including social/cognitive congruence and improved access to learning opportunities. Together these results suggest that integrating fourth-year medical students in anatomy teaching increases their anatomical knowledge and improves measures of perceived confidence in both teaching and anatomy knowledge. The thematic analysis revealed that this initiative has positive benefits for first-year students.