The NAEP Long-Term Trend Scales in Reading and Mathematics

For every subject assessed, NAEP reports on how well students in different demographic groups like race, gender, and region perform on the assessment. (NAEP does not report individual student scores.) How does NAEP summarize what students in these groups know and can do, and make comparisons among the achievements of these groups of students?

In long-term trend, NAEP created two separate scales for reading and mathematics ranging from 0 to 500, based on Item Response Theory (IRT). IRT is a set of statistical procedures useful in summarizing student performance across a collection of test exercises requiring similar knowledge and skills. All NAEP subject area scales are produced using these procedures.

Learn more about what the long-term trend reading and mathematics assessments measure.

Find out how scale scores relate to the long-term trend performance levels in reading and mathematics.