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More About NAEP Science

The NAEP science assessment presents a broad view of what America's students know and can do in science. The grade 8 assessment was administered in 2011 so that results from both the NAEP mathematics and science assessments in 2011 could be linked to results for the 2011 Trends in International Mathematics and Science Study (TIMSS). The results from the linking study will be presented in a separate report and will show how the performance of eighth-grade students in states and selected districts compares to international benchmarks.

On this page, learn more about:

The NAEP science framework

The National Assessment Governing Board oversees the development of NAEP frameworks that describe the specific knowledge and skills to be assessed in each subject. Frameworks incorporate ideas and input from subject area experts, school administrators, policymakers, teachers, parents, and others. The NAEP Science Framework PDF File (9.99 MB) describes the assessment content and how students' responses are evaluated. This framework shaped both the 2009 and 2011 science assessments.

The assessment exercises and scoring criteria were developed by a committee of content and measurement experts to capture the goals of the framework. The framework, which describes the goals of the science assessment and what kind of exercises it ought to feature, was created by the Board through a national comprehensive developmental process involving science teachers and researchers, measurement experts, policymakers, and members of the general public. The NAEP Science Committee was instrumental in developing the assessment, guided by the framework.

The assessment was designed to measure students' knowledge of three broad content areas reflecting the science content students are generally exposed to across the K-12 curriculum:

physical science,
life science, and
Earth and space sciences.

In addition to science content, four science practices describe how students use their science knowledge by measuring what they are able to do with the science content:

identifying science principles,
using science principles,
using scientific inquiry, and
using technological design.

See What Does the NAEP Science Assessment Measure? for further information about these dimensions.

Each of the above categories—content areas and science practices—should occupy a certain proportion of the assessment, as specified in the framework; see the target and actual distribution of science questions by category.

Assessment question formats

The assessment consisted of multiple-choice and constructed-response questions. Multiple-choice questions require students to select an answer from four to five options, while constructed-response questions require students to write either short or extended answers.

To learn more, see questions from previous NAEP science assessments in the NAEP Questions Tool.

NAEP also gives questionnaires to teachers, students, and schools that are part of the NAEP sample. Responses to these questionnaires give NAEP information about school policies affecting science instruction, as well as information about schools' educational resources.


Number of students who took the assessment 

Approximately 122,000 eighth-grade students in 7,290 schools participated in the 2011 NAEP science assessment. See details about participation rates and about sample size and target population.

State participation in the NAEP science assessment is voluntary and while most states participated in the 2009 assessment, all 50 states, the District of Columbia, and Department of Defense schools elected to participate in the 2011 assessment at grade 8. The schools and students participating in NAEP assessments are selected to be representative of all schools nationally and of public schools at the state level.

The NAEP program does not, and is not designed to, report on the performance of individual students. Instead, groups of the student population from representative national samples are assessed. For example, NAEP reports results for male and female students, Black students and White students, and students in different regions of the country. Samples are selected using a complex sampling design.

Permitted accommodations

For the 2011 science assessment, accommodations for students with disabilities (SD) and English language learners (ELL) were permitted for the entire sample of students. This differs from the 1996 and 2000 science assessments, in which data were collected from samples of students where assessment accommodations were not permitted and from samples of students where accommodations were permitted. In 2011, 2009 and 2005, accommodations were offered when a student had an Individualized Education Program (IEP) indicating the need for accommodation because of a disability, was protected under Section 504 of the Rehabilitation Act of 1973 because of disability, was identified as being an English language learner, and/or was normally offered accommodations in other assessment situations. All other students were asked to participate in the assessment under standard conditions. Prior to 1996, testing accommodations (e.g., extended time, small-group testing) were not permitted for SD and ELL students selected to participate in the NAEP science assessments. See the types of accommodations permitted for SD and ELL students.

Find inclusion and accommodations information for this assessment:

View the percentages of SD and ELL students identified, excluded, and assessed in science.
View the types of accommodations used and their rates of use

Assessment sample

NAEP assesses representative samples of students rather than the entire population of students. The sample selection process utilizes a probability sample design in which each school and each student has a known probability of being selected (the probabilities are proportionate to the estimated number of students in the grade assessed). Samples are selected according to a multistage design, with students drawn from within sampled public and private schools nationwide. See a diagram of sample selection for NAEP state assessments for a non-technical overview of the sampling process.

The Common Core of Data (CCD) file, a comprehensive list of operating public schools in each jurisdiction that is compiled each school year by NCES, served as the sampling frame for the selection of public schools in each state/jurisdiction.

The Private School Survey (PSS), survey of all U.S. private schools carried out biennially by the Census Bureau under contract to NCES, served as the sampling frame for private schools. While state results are based on samples of public schools only, the national results are based on the combined samples of public and private schools.

View the national and state sample sizes and target populations for NAEP 2011 science assessment at grade 8.
View the student and school participation rates.

Because each school that participated in the assessment, and each student assessed, represents only a portion of the larger population of interest, the results are weighted to make appropriate inferences between the student samples and the respective populations from which they are drawn. Sampling weights are adjusted for the disproportionate representation of some groups in the selected sample. This includes oversampling of schools with high concentrations of students from certain racial/ethnic groups and the lower sampling rates of students who attend very small schools. Read more about the technical aspects of the NAEP sample design.

Additional resources

Find out more about NAEP, the nation's only ongoing assessment of what students know and can do in various subjects.

View the NAEP 2011 Grade 8 Science Report Card.

Explore the most recent NAEP results in any subject on the website of The Nation’s Report Card.


Last updated 29 July 2012 (NB)