Detailed is a 20-year arduous journey to develop a statistically viable two-phase (AB) single-case two independent-samples randomization test procedure. The test is designed to compare the effectiveness of two different interventions that are randomly assigned to cases. In contrast to the unsatisfactory simulation results produced by an earlier proposed randomization test, the present test consistently exhibited acceptable Type I error control under various design and effect-type configurations, while at the same time possessing adequate power to detect moderately sized intervention-difference effects. Selected issues, applications, and a multiple-baseline extension of the two-sample test are discussed.




A previous version of this article incorrectly gave the month of publication of Gafurov & Levin (2020) as April. It has been corrected to March. An earlier version of this article mistakenly replaced ellipses with a capital letter K. This has been corrected.

Recommended Citation

Levin, J. R., Ferron, J. M., & Gafurov, B. S. (2019). An improved two independent-samples randomization test for single-case AB-type intervention designs: A 20-year journey. Journal of Modern Applied Statistical Methods, 18(1), eP3311. doi: 10.22237/jmasm/1556670480