BASIC SCORE INTERPRETATION INFORMATION FOR THE IOWA TEST OF
BASIC SKILLS (ITBS) AND THE COGNITIVE ABILITIES TEST (CogAT)
National Percentile Rank/Percentile Rank
(Abbreviated as “NPR” or “PR”)
The percentage of scores in a specified distribution that fall at or below the point of a
given score. Percentile Ranks range in value from 1 to 99, and indicate the status or
relative standing of an individual within a specified group by indicating the percent of
individuals in that group who obtained lower scores. For example, if a student earned a
72nd Percentile Rank in Language, this would mean he or she scored better than 72
percent of the students in a particular norm group who were administered that same test
of Language. This also implies that only 28 percent (100 - 72) of the norm group scored
the same or higher than this student.
(Abbreviated as “NS” or “S”)
The name stanine is simply a derivation of the term "standard-nine" scale. Stanines are
normalized standard scores, ranging in value from 1-9, whose distribution has a mean of
5. The higher the stanine number the better the performance of the student.
Standard Age Score
(CogAT only . . . Abbreviated as “SAS”)
The Standard Age Score scale is a normalized standard score scale for each battery
and the Composite. The SAS has a mean of 100 and a standard deviation of 16. It
permits educators to compare the rate and level of cognitive development of an
individual to other students in the same age group. For example, students who have an
SAS of 100 on the Verbal Battery have a rate and level of development of verbal
reasoning skills that is typical of their age group.