This package provides R functions for calculating basic effect size indices for single-case designs, including several non-overlap measures and parametric effect size measures, and for estimating the gradual effects model developed by Swan and Pustejovsky (2018). Standard errors and confidence intervals (based on the assumption that the outcome measurements are mutually independent) are provided for the subset of effect sizes indices with known sampling distributions.

The available non-overlap indices are:

  • Percentage of non-overlapping data (PND)
  • Percentage of all non-overlapping data (PAND)
  • Robust improvement rate difference (IRD)
  • Percentage exceeding the median (PEM)
  • Non-overlap of all pairs (NAP)
  • Tau non-overlap (Tau)
  • Baseline-corrected Tau (Tau-BC)
  • Tau-U (including baseline trend adjustment)

The available parametric effect sizes are:

  • Within-case standardized mean difference
  • Log response ratio (decreasing and increasing)
  • Log odds ratio
  • Log ratio of medians
  • The gradual effects model, which can be used to estimate log response ratios or log odds ratios in the presence of time trends during treatment and return-to-baseline phases.

The package also includes two graphical user interfaces (designed using Shiny) for interactive use, both of which are also available as web apps hosted through shinyapps.io:

Please note that the web apps should only be used for demonstration purposes. For research purposes, please install the R package and run the GUI through RStudio.

Installation

The package is available on the Comprehensive R Archive Network. To install it, you will first need to install R and RStudio. Both of these programs are freely available. Once you have these programs installed, run the following commands at the RStudio console prompt:

install.packages("SingleCaseES")

To install the latest development version directly from Github, type:

install.packages("devtools")
install.packages("sourcetools")
install.packages("shiny")
install.packages("markdown")
install.packages("ggplot2")
install.packages("purrrlyr")
devtools::install_github("jepusto/SingleCaseES", build_vignettes = TRUE, force = TRUE)

Getting started

The package includes two vignettes that demonstrate the syntax of the main functions and provide precise definitions and details about how each of the effect sizes are calculated. To view the vignettes, type the following:

browseVignettes("SingleCaseES")

A list of vignettes should then appear in your browser. Click on the hyperlinks to view them. Alternately, type the following line of code to open the introductory vignette:

vignette("Using-SingleCaseES")

Graphical user interface

To use the graphical user interface for basic effect sizes, you must first ensure that the SingleCaseES package is installed (following the directions above). To start the calculator, type the following commands at the RStudio console prompt:

The calculator should then open in your default web browser. To exit the calculator, close the window in which it appears.

To use the graphical user interface for the gradual effects model, type the following commands at the RStudio console prompt:

The calculator should then open in your default web browser.

Acknowledgement

The development of this R package was supported in part by the Institute of Education Sciences, U.S. Department of Education, through Grant R324U190002 to the University of Oregon. The contents of the package do not necessarily represent the views of the Institute or the U.S. Department of Education.

Citations

Please cite this R package as follows:

Pustejovsky, J. E., Chen, M., & Swan, D. M. (2021). SingleCaseES: A calculator for single-case effect size indices. R package version 0.5.0. Retrieved from https://github.com/jepusto/SingleCaseES

Please cite the web applications as follows:

Pustejovsky, J. E., Chen, M., & Swan, D. M. (2021). Single-case effect size calculator (Version 0.5.0) [Web application]. Retrieved from https://jepusto.shinyapps.io/SCD-effect-sizes

Swan, D. M. & Pustejovsky, J. E. (2017). gem_scd: A web-based calculator for the Gradual Effects Model (Version 0.1.0) [Web application]. Retrieved from: https://jepusto.shinyapps.io/gem-scd