Percentiles: These scores show how a student's performance compares to others tested during test development. A student who scores at the 50th percentile performed at least as well as 50 percent of students his age in the development of the test.

Z-Scores: These scores range from +4 to -4 and have an average of zero. Positive scores are above average. Negative scores are below average.

T-Scores: Have an average of 50 and a standard deviation of 10. Scores above 50 are above average. Scores below 50 are below average. .

Z-Scores: These scores range from +4 to -4 and have an average of zero. Positive scores are above average. Negative scores are below average.

T-Scores: Have an average of 50 and a standard deviation of 10. Scores above 50 are above average. Scores below 50 are below average. .