Olly11
Posts: 1
Joined: Wed Aug 15, 2018 10:42 am
Occupation: Student

### Comparing Scores from Tests on Different Scales

I am trying to compare individuals performance on math vs their performance on reading. The reading tests are scored on a 0-100 scale and the math test is scored on a 0-25 scale. How can I compare individual's scores in a statistically sound way?

dcnick96
Moderator
Posts: 532
Joined: Wed Jul 25, 2007 7:59 pm

### Re: Comparing Scores from Tests on Different Scales

Hello, there. You want to "normalize" your data. Meaning, you want to find a common scale between the two tests.

I would change the scores to percentages, and then compare the percentages. For example, a 90/100 on the reading test would be 90%. A 23/25 on the math test would be 92%. So, in this case, the student would have scored slightly higher in math than in reading. If you want to make an overall assessment across multiple individuals, simply take the average percentage for both math and reading to compare the two.

I hope this helps. Write back if you have further questions. Good luck!
Deana