Technology Enabled Assessments: An Investigation of Scoring Models for Scaffolded Tasks

While significant progress has been made in recent years on technology enabled assessments (TEAs), including assessment systems that incorporate scaffolding into the assessment process, there is a dearth of research regarding psychometric scoring models that can be used to fully capture students' knowledge, skills and abilities as measured by TEAs. This investigation provides a comparison of seven scoring models applied to an operational assessment system that incorporates scaffolding into the assessment process and evaluates student ability estimates derived from those models from a validity perspective. A sequential procedure for fitting and evaluating increasingly complex models was conducted. Specifically, a baseline model that did not account for any scaffolding features in the assessment system was established and compared to three additional models that each accounted for scaffolding features using a dichotomous, a polytomous and a testlet model approach. Models were compared and evaluated against several criteria including model convergence, the amount of information each model provided and the statistical relationships between scaled scores and a criterion measure of student ability. Based on these criteria, the dichotomous model that accounted for all of the scaffold items but ignored local dependence was determined to be the optimal scoring model for the assessment system used in this study. However, if the violation against the local independence assumption is deemed unacceptable, it was also concluded that the polytomous model for scoring these assessments is a worthwhile and viable alternative. In any case, the scoring models that accounted for the scaffolding features in the assessment system were determined to be better overall models than the baseline model that did not account for these features. It was also determined that the testlet model approach was not a practical or useful scoring option for this assessment system. Given the purpose of the assessment system used in this study, which is a formative tool that also provides instructional opportunities to students during the assessment process, the advantages of applying any of these scoring models from a measurement perspective may not justify the practical disadvantages. For instance, a basic percent correct score may be completely dependent on the specific items that a student took but it is relatively simple to understand and compute. On the other hand, scaled scores from these scoring models are independent of the items from which they were calibrated from, but ability estimates are more complex to understand and derive. As the assessment system used in this study is a low stakes environment that is mostly geared towards learning, the benefits of the scoring models presented in this study need to be weighed against the practical constraints within an operational context with respect to time, cost and resources

Making Science Accessible to Students with Significant Cognitive Disabilities

The publication of A Framework for K-12 Science Education (National Research Council, 2012) and the Next Generation Science Standards (NGSS Lead States, 2013) have created a need for new alternate content standards and alternate assessments in science that are linked to the new general education science standards. This article describes how a consortium of four states used Evidence-Centered Design (Mislevy, Steinberg, & Almond, 2003) and Universal Design for Learning (CAST, 2012) to develop alternate science content standards and assessments. A set of 43 alternate science content standards was created and an alternate assessment at each of three grade spans. Evidence that supports appropriateness of the alternate standards for students with SCD and fidelity of representation of the Framework is presented. One cycle of testlet/item development was conducted. Results of a pilot test (251 items; 1,606 students) are presented. Evidence for validity and accessibility of the alternate assessment is presented. Major findings include that the assessment items met accessibility, bias and sensitivity, and content requirements, and that students were able to understand and respond to assessment items. Data from a pilot assessment provided evidence of the accessibility of the standards and assessments. The implications of this work for teaching science to students with SCD and preliminary efforts to develop supports for teachers are discussed

Revised CMS Global Calorimeter Trigger Functionality & Algorithms

The Global Calorimeter Trigger (GCT) is a device which uses data from the CMS calorimeters to search for jets, produce isolated and non-isolated electron lists and compute all the transverse and missing transverse energy sums used for the Level-1 trigger decision (L1A). GCT performs these functions by receiving and processing the data from the Regional Calorimeter Trigger (RCT) and transmitting a summary to the Global Trigger (GT) which computes the L1A decision. The GCT must also transmit a copy of the RCT and GCT data to the CMS DAQ. The vast amount of data received by the GCT (230 Gb/s) as well as the necessity for data sharing required by the jet finder impose severe constrains on the GCT design. This paper presents an overview of the revised design, in particular, the algorithms, data flow and associated latency within the revised GCT

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum

Performance of CMS muon reconstruction in pp collision events at sqrt(s) = 7 TeV

The performance of muon reconstruction, identification, and triggering in CMS has been studied using 40 inverse picobarns of data collected in pp collisions at sqrt(s) = 7 TeV at the LHC in 2010. A few benchmark sets of selection criteria covering a wide range of physics analysis needs have been examined. For all considered selections, the efficiency to reconstruct and identify a muon with a transverse momentum pT larger than a few GeV is above 95% over the whole region of pseudorapidity covered by the CMS muon system, abs(eta) < 2.4, while the probability to misidentify a hadron as a muon is well below 1%. The efficiency to trigger on single muons with pT above a few GeV is higher than 90% over the full eta range, and typically substantially better. The overall momentum scale is measured to a precision of 0.2% with muons from Z decays. The transverse momentum resolution varies from 1% to 6% depending on pseudorapidity for muons with pT below 100 GeV and, using cosmic rays, it is shown to be better than 10% in the central region up to pT = 1 TeV. Observed distributions of all quantities are well reproduced by the Monte Carlo simulation.Comment: Replaced with published version. Added journal reference and DO