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Note 4: National Assessment of Educational Progress (NAEP) (2006)

The National Assessment of Educational Progress (NAEP), governed by the National Assessment Governing Board (NAGB), is administered regularly in a number of academic subjects. Since its creation in 1969, NAEP has had two major goals: to assess student performance reflecting current educational and assessment practices and to measure change in student performance reliably over time. To address these goals, the NAEP includes a main assessment and a long-term trend assessment. The two assessments are administered to separate samples of students at separate times, use separate instruments, and measure different educational content. Thus, results from the two assessments should not be compared.


Indicators 6, 12, 13, 14, 15, 18, and 24 are based on the main NAEP. Begun in 1990, the main NAEP periodically assesses students’ performance in several subjects in grades 4, 8, and 12, following the curriculum frameworks developed by the NAGB and using the latest advances in assessment methodology. NAGB develops the frameworks using standards developed within the field, using a consensus process involving educators, subject-matter experts, and other interested citizens. Each round of the main NAEP includes a student assessment and background questionnaires (for the student, teacher, and school) to provide information on instructional experiences and the school environment at each grade.

Before 2002, the main NAEP national sample was an independently selected national sample. However, beginning in 2002, the NAEP national sample was obtained by aggregating the samples from each state. As a result, the size of the national sample increased in 2002, which means that smaller differences between estimates from different administrations and different types of students can now be found to be statistically significant than can be detected from assessment results prior to 2002.

The content and nature of the main NAEP evolve to match instructional practices, so the ability to measure change reliably over time is limited. As standards for instruction and curriculum change, so does the main NAEP. As a result, data from different assessments are not always comparable. However, recent main NAEP assessment instruments for mathematics, science, and reading have typically been kept stable for short periods, allowing for a comparison across time. For example, from 1990 to 2005, assessment instruments in the same subject areas were developed using the same framework, shared a common set of questions, and used comparable procedures to sample and address student populations. For some subjects that are not assessed frequently, such as civics and the arts, no trend data are available.

The main NAEP results are reported in The Condition of Education in terms of both average scale scores and achievement levels. The achievement levels define what students who are performing at Basic, Proficient, and Advanced levels of achievement should know and be able to do. NAGB establishes achievement levels whenever a new main NAEP framework is adopted. These achievement levels have undergone several evaluations but remain developmental in nature and continue to be used on a trial basis. Until the Commissioner of NCES determines that the levels are reasonable, valid, and informative to the public, they should be interpreted and used with caution. The policy definitions of the achievement levels that apply across all grades and subject areas are as follows:

Unlike estimates from other sample surveys presented in this report, NAEP estimates that are unstable (large standard error compared with the estimate) are not flagged as potentially unreliable. This practice for NAEP estimates is consistent with the current output from the NAEP online data analysis tool. The reader should always consult the appropriate standard errors when interpreting these findings. For additional information on NAEP, including technical aspects of scoring and assessment validity and more specific information on achievement levels, see

Student Accommodations

Until 1996, the main NAEP assessments excluded certain subgroups of students identified as “special needs students,” including students with disabilities and students with limited English proficiency. For the 1996 and 2000 mathematics assessments and the 1998 and 2000 reading assessments, the main NAEP included a separate assessment with provisions for accommodating these students (e.g., extended time, small group testing, mathematics questions read aloud, and so on). Thus, for these years, there are results for both the unaccommodated assessment and the accommodated assessment. For the 2002, 2003, and 2005 reading and 2003 and 2005 mathematics assessments, the main NAEP did not include a separate unaccommodated assessment; only a single accommodated assessment was administered. The switch to a single accommodated assessment instrument was made after it was determined that accommodations in NAEP did not have any significant effect on student scores. Indicators 12 and 13 present NAEP results with and without accommodations.


Indicator 16 is based on the long-term trend NAEP and measures basic student performance in reading, mathematics, science, and writing. Since the mid-1980s, the long-term trend NAEP has used the same instruments to provide a means to compare performance over time, but they do not necessarily reflect current teaching standards or curricula. Results have been reported for students at ages 9, 13, and 17 in mathematics, reading, and science, and at grades 4, 8, and 11 in writing. Results from the long-term trend NAEP are presented as mean scale scores because, unlike the main NAEP, the long-term trend NAEP does not define achievement levels.