Statistical Analysis for Education and Psychology Researchers

where xi is the original score and J is a constant from which each score is subtracted so
that the smallest score is 0.5. J is the largest score+0.5. In SAS code this would be
newx=sqrt(j−oldx).

Figure 5.14: Histogram and normal

probability plot for arcsine

transformed variable ‘CORRE’—

percentage correct easy reading

passage

Interpretation of Transformed Scores

Choosing a statistical test 157