Friedman testFrey, B. (2018). The SAGE encyclopedia of educational research, measurement, and evaluation (Vols. 1-4). Thousand Oaks,, CA: SAGE Publications, Inc. doi: 10.4135/9781506326139
This source describes the non-parametric version of the repeated measures analysis of variance. The Friedman test is used when one or more of the repeated measures ANOVA assumptions are not met.