Validity: Q vs. R
This study deals with political ideology, in the form of Q sorts of 80 self-referent statements provided by more than 50 respondents, the P set being cross-sectional. The resulting data set was split up into three equivalent P samples, each of which was submitted independently to Q factor analysis. Also, it was split up into four equivalent item samples, each of which was submitted independently to R factor analysis. Comparison of Q analysis loadings with R analysis z-scores and of Q analysis z-scores with R analysis loadings shows a limited amount of cross-validity. With respect to (meta-)reliability, the three cases of Q factor analysis are strikingly similar; the fours cases of R factor analysis, however, turn out to be rather dissimilar.