A New Four-Arm Within-Study Comparison Data on Math and Vocabulary Training R package WSCdata version 0.1.2 This dataset was collected using a new four-arm within-study comparison design. The study aimed to examine the impact of a mathematics training intervention and a vocabulary study session on post-test scores in mathematics and vocabulary, respectively. The innovative four-arm within-study comparison design facilitates both experimental and quasi-experimental identification of average causal effects. Software Depends: R (>= 4.1.0) Suggests: testthat (>= 3.0.0), tidyverse Jingru Zhang <jzhang2637@wisc.edu> Comprehensive R Archive Network (CRAN) Bryan Keller [aut, cph], Sangbaek Park [aut, ctb], Jingru Zhang [aut, cre] MIT + file LICENSE (https://CRAN.R-project.org/package=WSCdata/LICENSE) 2025-11-20 application/tgz https://CRAN.R-project.org/package=WSCdata doi:10.32614/CRAN.package.WSCdata