Edgovnationsreportcardlttdata when making multiple

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Unformatted text preview: differences and not mere chance. In NAEP, the Benjamini-Hochberg False Discovery Rate (FDR) procedure is used to control the expected proportion of falsely rejected hypotheses relative to the number of comparisons that are conducted. A detailed explanation of this procedure can be found at http:/ /nces.ed.gov/ nationsreportcard/tdw/analysis/infer.asp. NAEP employs a number of rules to determine the number of comparisons conducted, which in most cases is simply the number of possible statistical tests. When comparing multiple years, however, the number of years does not count toward the number of comparisons. Setting Performance Levels Performance levels are distinct from the achievement levels that have been set for main NAEP assessments. To help interpret NAEP long-term trend results, the reading and mathematics scales were each divided into five successive levels of performance (150, 200, 250, 300, and 350). A “scale anchoring” process was used to define what it meant to score at each of these levels. Questions were identified that were more likely to be answered correctly by students performing at each level on the scale and less likely to be answered correctly by students performing at the next lower level. Students at a given level had to have at least a 65 to 80 percent probability of answering the question correctly; students at the next lower level had a much lower probability of answering it correctly. The difference in probabilities between adjacent levels had to exceed 30 percent. Content spets for each subject examined these empirically selected question sets and used their professional judgment to characterize each level. The reading scale anchoring was conducted on the basis of the 1984 assessment, and the scale anchoring for mathematics trend reporting was based on the 1986 assessment. TRENDS IN ACADEMIC PROGRESS 2012 53 T ECHNICAL NOTES Race/Ethnicity Results are presented for students in three mutually exclusive racial/ethnic groups: White, Black, and Hispanic. (Note that reading results for Hispanic students were not available prior to 1975.) Performance results for Asian/Pacific Islander students have not been included in long-term trend reports because reporting standards were not met in some of the earlier assessment years. Results for those years in which they could be reported are available in the NAEP Data Explorer at http:/ /nces.ed.gov/nationsreportcard/lttdata/. Results for American Indian (including Alaska Native) students are not reported separately because there were too few students sampled in this group for the results to be statistically reliable. Data for all stu­ dents, regardless of whether their racial/ethnic group was reported separately, were included in computing the overall national results. Results by students’ race/ethnicity are presented in this report based on information collected from two different sources: Observed Race/Ethnicity. Prior to 2004, students participating in the long-term trend assessment were assigned to a racial/ethnic category based on the assessment administrator’s observation....
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This document was uploaded on 02/28/2014.

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