I performed a One-Way Anova on the scores and there was a significant difference between the two groups.

However, I then converted the scores to z-scores (using the larger group as the population mean) and the smaller group had a z-score of -.382 (which would not be significant, correct?)

Under what circumstances do you convert to z-scores? Is it ok to use the raw means to do an ANOVA?

Thank you!