Post-hoc comparisons for Friedman test
As a non-parametric test of mean differences for dependent samples SPSS implements the Friedman test. However, SPSS does not provide post-hoc tests to decide which groups are significantly different from each other. Schaich and Hamerle (1984) as well as Conover (1971, 1980) propose such post-hoc tests that are based upon the mean rank differences of the groups. These procedures are detailed in Bortz, Lienert and Boehnke (2000, pp. 275).
Note: Since version 18 SPSS provides comparable post-hoc tests by default.
- Bortz, J., Lienert, G. & Boehnke, K. (2000). Verteilungsfreie Methoden in der Biostatistik. Berlin: Springer. ISBN: 3540675906.
- Conover, W. J. (1971, 1980). Practical nonparametric statistics. New York: Wiley. ISBN: 0471168513.
- Schaich, E. & Hamerle, A. (1984). Verteilungsfreie statistische Prüfverfahren. Berlin: Springer. ISBN: 3540137769.