scdtb Release Party

In the world of education research, RCTs are one of the research designs that can attain a rating of Meets WWC Standards Without Reservations. Another research design that can attain this rating is the single case design. Single case designs are "experiments in which one unit is observed repeatedly during a certain period of time under different levels of at least one manipulated variable." When it is not possible to get enough participants to demonstrate causal effects with a well-powered RCT, researchers might try to see if it is possible to demonstrate causal effects using one (or a few) participant(s) in a single case design.

The 'scdtb' (Single Case Design Toolbox) R package has a collection of functions which can be used to visualize and analyze data from single case designs. The main functions include:

• raw_plot(), for visualizing raw data from different types of single case designs
• nap(), for computing the nonoverlap of all pairs
• mixed_model_analysis(), for running a type of mixed effects model that is useful for single case designs
• cross_lagged(), to analyze cross lagged correlations
• randomization_test, to compare observed outcome differences to a distribution of differences obtained through permutation

All of these tools in 'scdtb' v0.1.0 were obtained or modified from the What Works Clearing House Procedures and Standards Handbook Version 5.0 or from the n=1 section of Small Sample Size Solutions. The 'scdtb' package also contains datasets that were used as examples in these two resources.

The 'scdtb' package also contains two 'shiny' applications. The first can be accessed through the scdtb() function. It can also be accessed through the mightymetrika website. This function allows the user to upload a csv file with single case design data. Once data is uploaded to the application, the user can run an analysis using the five functions mentioned above (although for a specific design, only a subset of the functions might be applicable). In the coming weeks, there will be additional blog posts outlining how to use the scdtb() 'shiny' app to analyze single case design data using the datasets contained in the 'scdtb' package.

The napjack() function is a card game to help users get a better feel for looking at analysis results from single case designs. The Roxygen2 documentation for the game describes the game as follows:

The game consists of four phases: baseline 1, treatment 1, baseline 2, and treatment 2. In each phase, the player deals six cards and has the option to swap cards within a row once per phase. After all four phases are completed, the game is scored based on the analysis of the dealt cards using non-overlap of all pairs (NAP) and mixed effects modeling.

An upcoming blog post play and explain a few hands of napjack.