TECH DEMO: Free Design and Analysis Software for Use with R and SAS from the Penn State Methodology Center

This technology demonstration will showcase new software and other online methodological resources developed at The Methodology Center at Penn State. New SAS macros and R code will be demonstrated and distributed. Online resources for teaching methods courses and for learning new methods will also be displayed. The software will include extensions of time-varying effect modeling (TVEM), a new estimation method for latent class analysis (LCA) with a distal outcome, and a set of tools for designing factorial experiments. All online resources will be available on the Center’s website at methodology.psu.edu; all software and corresponding users’ guides will be available free-of-charge on the website and will be distributed on USB drives during the technology demonstration.

The following software will be demonstrated: (1) an new SAS macro for estimating time-varying effect models that accommodates sampling weights; (2) a revised SAS macro for latent class analysis with a distal outcome that improves estimates of class-specific means or probabilities and also includes standard errors and p-values; (3) a set of tools for factorial experiments in R that (a) performs sample size and power calculations, (b) conveniently generates random assignments of participants to experimental conditions, and (c) calculates the relative costs of implementing different experimental designs; and (4) a new SAS macro for fitting time-varying effect models to ordinal outcome variables.

Two other types of online resources will also be displayed or distributed. A new video introducing time-varying effect modeling will be displayed to interested attendees, and other introductory videos will also be available for viewing. New resources (including PowerPoint slides, article lists, and exercises) for instructors of methods courses will also be included on the USB drives. These teaching resources will be available for LCA and TVEM.

Information will be available about other online resources and software created and maintained by The Methodology Center at Penn State. Some of our other software products include a STATA plug-in to conduct LCA and a SAS PROC and R package to analyze data from SMART to inform development of adaptive interventions. Demonstrations and information will be presented in the context of empirical data on the etiology or prevention of substance use and related behaviors. Attention will be given to practical implementation of the statistical methods using the demonstrated software, as well as recent features that have been incorporated into the software. Attendees of the annual meeting will be able to provide suggestions for future online resource development.