The process of developing achievement levels involves the judgments of informed, well-qualified people from throughout the nation and its territories. Approximately 20 persons served on each of three grade-level panels to develop NAEP science achievement levels. These 60 people included teachers (about 55 percent), other educators (about 15 percent), and members of the general public (about 30 percent). To the extent possible, the panels were proportionally representative of the nation's population with respect to region, race/ethnicity, and gender.
The panels for science were convened in 1996; however, before setting the science NAEP achievement levels, the National Assessment Governing Board reviewed achievement level data from other sources. The Board judged that some levels were set too high and some were set too low. The Board analyzed the relationship of cut scores to percentages of students scoring at or above different levels and adopted levels that it judged to be reasonable. The achievement levels set for the science NAEP were used in reporting results for the 1996 assessment and subsequent assessments.
In 2009, a new framework was introduced by the Board to reflect changes in the field of science. Along with the introduction of a new framework, new achievement level descriptions and cut scores were established. The assessment resulting from the 2009 framework started a new NAEP science trend line so results from 2009 cannot be compared with results of previous science assessments. Whenever changes are made to a framework, efforts are made to maintain the trend lines that permit the reporting of changes in student achievement over time. If, however, the nature of the changes made to an assessment is such that the results would not be comparable to earlier assessments, a new trend line is started. See a comparison of the two frameworks.
A complete description of the science achievement levels for grades 4, 8, and 12 is available at http://nces.ed.gov/nationsreportcard/science/achieveall.asp
NOTE: As provided by law, the achievement levels are to be used on a trial basis and should be interpreted with caution. However, both NCES and the Board believe that these performance standards are useful for understanding trends in student achievement.