Use of the Randomization Test in Single-Case Research

Abstract

The purpose of this study was to illustrate the use of the randomization test for single-case research designs (SCR; Kratochwill & Levin, 2010). To demonstrate the application of this approach, a systematic replication of Grünke, Wilbert, and Calder Stegemann (2013) was conducted to evaluate the effects of a story map to improve the reading comprehension skills
of five elementary students with learning disabilities in Germany. A multiple-baseline design (Baer, Wolf, & Risley, 1968) was used to evaluate the effectiveness of the story mapping instruction in teaching students the key story grammar elements in a reading passage. However, unlike in traditional multiple-baseline designs, intervention and withdrawal phases were applied at randomly determined points. Results indicated that the use of story maps increased the students’ recall and comprehension of the stories from baseline to intervention, and continued during maintenance. A randomization test confirmed that the differences between baseline and intervention were statistically significant. Findings, limitations, and implications of the use of randomization tests in SCR are discussed.