National Percentile (NP)
A National Percentile score ranks test performances from 1 to 99. For example, an NP score (or rank) of 65 means that the student’s score is higher than the scores of 65 percent of the students in the norm group for that grade and time of year.

Normal Curve Equivalent (NCE)
The Normal Curve Equivalent was developed specifically to compute averages and calculate differences when comparing test scores. Like NPs, NCEs range from 1 to 99. NCEs are also the preferable score when averaging scores or when comparing gains, losses, or trends across content areas.