description- – The Turbulent Eddy Profiler (TEP) developed at the University of Massachusetts Microwave Remote Sensing Laboratory (MIRSL) provides three dimensional fine-scale imagery of the intensity of clear-air backscatter and motion of the air with 30 meter resolution between 200 m and 2.0 km altitude. This dissertation presents the design and operation of the updated TEP system deployed in Leon, Kansas during CASES'99 experiment. Both Doppler Beam Swinging (DBS) techniques and Spaced Antenna (SA) techniques for estimating horizontal winds were applied to TEP data collected during CASES'99 experiment. This dissertation compares the results from both techniques with the simultaneous in situ Tethered Lifting System (TLS) data. Good agreement between both methods is observed at intermediate altitudes, however, DBS appears to be preferable to SA at higher altitudes where SNR is low; while SA appears to perform better at the low altitudes, where ground clutter competes with the clear-air echo.
collectiondatepublishercreator description- – The goal of this study was to identify the effects of state-level standards-based reform on teaching and learning, paying particular attention to the state test and associated stakes. On-site interviews were conducted with 360 educators (elementary, middle, and high school teachers) in 3 states (120 in each state) attaching different stakes to the test results. In Kansas, state test results were used to determine school accreditation but had no stakes for students. In Michigan, school accreditation was determined by student participation in and performance on the state test and students received an endorsed diploma and were eligible for college tuition credit if they scored above a certain level on the 11th grade tests. In Massachusetts, school ratings were based on the percentage of students in different performance categories and students, starting in 2003, had to pass the 10th grade test to graduate. No clear relationship was found between the level of the stakes attached to the state test and the influence of the state standards on classroom practice. Findings suggest that other factors are at least as important, if not more so, in terms of encouraging educators to align classroom curricula with these standards. At the same time, as the stakes attached to the test results increased, the test seemed to become the medium through which the standards were interpreted. Taken together, findings suggest that stakes are a powerful level for effecting change, but one whose effects are uncertain. A one-size-fits-all model of standards, tests, and accountability in not likely to bring about the greatest motivation and learning for all students. Three appendixes contain a grid describing state testing programs, the interview protocol, and the methodology.
subjectcollectiondatepublishercreator description- – The National Assessment of Educational Progress (NAEP) is the only nationally representative, continuing assessment of what America's students know and can do in various subject areas. As one part of the student population, special-needs students, which refer to both students with disabilities (SDs) and students with limited English proficiencies (LEPs), are also included in NAEP assessments. Beginning in 1996, NAEP began offering test accommodations to special-needs students in order for them to participate meaningfully in the assessments. Although the use of accommodations increased participation rates in NAEP, the validity of results obtained under accommodated testing situations has not been fully established. Inferences drawn from test results are valid only if the analysis models fit not only the calibration sample as a whole but also the student subgroups within the calibration sample. The objective of this study is to examine whether the scaling models fit the data from special-needs students with accommodations in NAEP. The study used data from NAEP 2000 Grade 8 mathematics state assessment and examined overall model-data fit, item fit and person fit. Results showed the LEP group had no significant subscale misfit, but the SD group had significant misfit in two of the five mathematics subscales. The SD group also had more misfit items across the five subscales than the LEP group had. One possible reason might be that the SD group is a more heterogeneous group than the LEP group. With students having various kinds of disabilities and varying degrees of disabilities, a few types of accommodations in NAEP assessment did not satisfy individual needs adequately for the SD group. Item fit analysis revealed that the dichotomization and collapsing of item categories for extended constructed-response items in scaling is problematic and may result in significant item misfit. Person fit analysis with respect to gender groups, racial groups and accommodation types shows significant results in some but not all subscales.
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