Computing a mean difference across studies that used measurement scales with different possible numbers of score points is meaningless. What is suggested in this topic to overcome this problem?

Question

Quizplus · Accepted Answer

Converting to a standardized measurement scale or using regression analysis would not address the issue of different possible numbers of score points. Weighting the average value of d would not be meaningful because the d values would not be comparable across studies. Using a measure of effect size such as Cohen's d would allow for the comparison of mean differences across studies with different possible numbers of score points.

Computing a Mean Difference Across Studies That Used Measurement Scales