Since the 1970s, the National Assessment of Educational Progress (NAEP) has monitored student performance in mathematics and reading through long-term trend (LTT) assessments. These assessments measure students’ educational progress over long time periods to look for and monitor trends in performance. Results from the 2020 LTT reading assessment at ages 9 and 13 are based on nationally representative samples of 8,400 nine-year-olds and 8,900 thirteen-year-olds. Results from the 2020 LTT mathematics assessment at ages 9 and 13 are based on the nationally representative samples of 8,400 nine-year-olds and 8,900 thirteen-year-olds. Typically, the LTT assessments in reading and mathematics are also administered at age 17; however, the 2020 administration of the LTT assessment at age 17 was necessarily postponed to ensure the saftey of students, school personnel, and test administrators.
Unlike the main NAEP assessments, which develop assessment instruments that reflect current educational content and assessment methodology, measuring trends in student achievement over time requires that LTT assessments remain consistent.
However, in 2004, changes were made to the LTT assessment design, and a study was conducted to ensure that results under the new design were comparable to the 1971–1999 results.
The LTT assessment measures students’ knowledge in mathematics and reading. Survey questionnaires, administered to students, teachers, and school administrators, who participate in an LTT assessment, are used to collect and report contextual information about the students’ learning experience in and out of the classroom.
Student performance on the NAEP LTT assessment is presented in two ways: scale scores and performance levels:
Scale scores represent the average performance of students who took the LTT assessment in mathematics and reading. Scores are aggregated and reported for the nation and groups of students based on gender, race/ethnicity, etc.
Performance levels are reported as the percentages of students attaining specific levels of performance corresponding to five points on the NAEP long-term trend reading and mathematics scales (150, 200, 250, 300, and 350).