NOTE: The arrowheads point to samples for which assessment results were already in the NAEP reporting metric in preparation for the 2008 reading long-term trend (LTT) assessment. The purpose of the bridging sample was to convert the standard NAEP booklet design used in the 1999 LTT assessment to the new design planned for the 2004 long-term trend assessment as well as take into account the addition of accommodated samples. (In the block labeled "Randomly Equivalent Samples (A)," the (A) refers to students in the sample who are not identified as students with disabilities or English language learners.) For more information on the 2004 bridge study, please refer to the 2004 LTT report.
SOURCE: U.S. Department of Education, Institute of Education Sciences, National Center for Education Statistics, National Assessment of Educational Progress (NAEP), 2008 Reading Long-Term Trend Assessment.