Why do multiple percentiles sometimes have the same RIT score?

Document created by Community User on Jan 25, 2017Last modified by Community User on Jul 26, 2020
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Question
Why do multiple percentiles have the same RIT score?

On the Student Status Percentiles chart in Appendix C.1 of the Norms study, some RIT scores apply to multiple percentiles. For example, the fall math kindergarten RIT score of 145 is listed for the percentiles 66, 67, and 68.

This means that more than 1% of testers received the specified RIT score in the norms study. As there are only 100 possible percentile scores, but RIT scores in the percentile charts for math range from 111-283, some percentiles will have more than one RIT score assigned to them.

How does this affect which percentile shows on reports?
Students will be placed in the appropriate percentile based on the unrounded RIT score. For example, if a particular RIT score corresponds to the 50th, 51st, and 52nd percentile, a student in the 50th percentile would have a lower unrounded RIT score than a student in the 52nd percentile.