For every subject assessed, NAEP reports on how well students in different demographic groups (such as 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 achievement of these groups of students?
For the arts assessment, NAEP created a scale for music and visual arts responding questions that ranged from 0 to 300 and was based on statistical procedures called 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. Visual arts creating questions were reported as the average percentage of the maximum possible scores from 0 to 100.
To give meaning to the levels of the arts scale, it is useful to create an item map. An item map is a representation of the skills and abilities demonstrated by students at various levels of the NAEP scale. The scale scores on the left of the map represent the average scores for students who were likely to get the questions correct or partially correct. Because achievement levels were not set for the 2008 arts assessment, the 2008 arts item maps indicate the scores for the 25th and 75th percentiles rather than achievement levels. Explore the visual arts and music item maps.