The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Julian R Betts - One of the best experts on this subject based on the ideXlab platform.
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does student sorting invalidate value added models of teacher effectiveness an Extended Analysis of the rothstein critique
Education Finance and Policy, 2011Co-Authors: Cory Koedel, Julian R BettsAbstract:Value-added modeling continues to gain traction as a tool for measuring teacher performance. However, recent research questions the validity of the value-added approach by showing that it does not mitigate student-teacher sorting bias (its presumed primary benefit). Our study explores this critique in more detail. Although we find that estimated teacher effects from some value-added models are severely biased, we also show that a sufficiently complex value-added model that evaluates teachers over multiple years reduces the sorting bias problem to statistical insignificance. One implication of our findings is that data from the first year or two of classroom teaching for novice teachers may be insufficient to make reliable judgments about quality. Overall, our results suggest that in some cases value-added modeling will continue to provide useful information about the effectiveness of educational inputs. © 2011 Association for Education Finance and Policy
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does student sorting invalidate value added models of teacher effectiveness an Extended Analysis of the rothstein critique
Education Finance and Policy, 2011Co-Authors: Cory Koedel, Julian R BettsAbstract:Value-added modeling continues to gain traction as a tool for measuring teacher performance. However, recent research questions the validity of the value-added approach by showing that it does not mitigate studentteacher sorting bias (its presumed primary benefit). Our study explores this critique in more detail. Although we find that estimated teacher effects from some valueadded models are severely biased, we also show that a sufficiently complex value-added model that evaluates teachers over multiple years reduces the sorting bias problem to statistical insignificance. One implication of our findings is that data from the first year or two of classroom teaching for novice teachers may be insufficient to make reliable judgments about quality. Overall, our results suggest that in some cases value-added modeling will continue to provide useful information about the effectiveness of educational inputs.
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does student sorting invalidate value added models of teacher effectiveness an Extended Analysis of the rothstein critique
Research Papers in Economics, 2009Co-Authors: Cory Koedel, Julian R BettsAbstract:Value-added modeling continues to gain traction as a tool for measuring teacher performance. However, recent research (Rothstein, 2009, forthcoming) questions the validity of the value-added approach by showing that it does not mitigate student-teacher sorting bias (its presumed primary benefit). Our study explores this critique in more detail. Although we find that estimated teacher effects from some value-added models are severely biased, we also show that a sufficiently complex value-added model that evaluates teachers over multiple years reduces the sorting-bias problem to statistical insignificance. One implication of our findings is that data from the first year or two of classroom teaching for novice teachers may be insufficient to make reliable judgments about quality. Overall, our results suggest that in some cases value-added modeling will continue to provide useful information about the effectiveness of educational inputs.
Mikael Sjodin - One of the best experts on this subject based on the ideXlab platform.
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integrating mixed transmission and practical limitations with the worst case response time Analysis for controller area network
Journal of Systems and Software, 2015Co-Authors: Saad Mubeen, Jukka Makiturja, Mikael SjodinAbstract:HighlightsWe extend the worst-case response-time Analysis for Controller Area Network (CAN) to support realistic CAN controllers and protocols.The Extended Analysis supports various transmission patterns including mixed messages that are implemented by several higher-level protocols for CAN that are used in the automotive industry today.The Extended Analysis also considers practical limitations in the CAN controllers and device drivers such as abortable and non-abortable transmit buffers. The existing worst-case response-time Analysis for Controller Area Network (CAN) calculates upper bounds on the response times of messages that are queued for transmission either periodically or sporadically. However, it does not support the Analysis of mixed messages. These messages do not exhibit a periodic activation pattern and can be queued for transmission both periodically and sporadically. They are implemented by several higher-level protocols based on CAN that are used in the automotive industry. We extend the existing Analysis to support worst-case response-time calculations for periodic and sporadic as well as mixed messages. Moreover, we integrate the effect of hardware and software limitations in the CAN controllers and device drivers such as abortable and non-abortable transmit buffers with the Extended Analysis. The Extended Analysis is applicable to any higher-level protocol for CAN that uses periodic, sporadic and mixed transmission modes.
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worst case response time Analysis for mixed messages with offsets in controller area network
Emerging Technologies and Factory Automation, 2012Co-Authors: Saad Mubeen, Jukka Makiturja, Mikael SjodinAbstract:The existing response-time Analysis for Controller Area Network (CAN) does not support mixed messages that are scheduled with offsets. Mixed messages are implemented by several high-level protocols for CAN that are used in the automotive industry. We extend the existing offset-based Analysis which is applicable to any high-level protocol for CAN that uses periodic, sporadic and mixed transmission of messages. Moreover, we implement the Extended Analysis as a standalone simulator that will be integrated as a plug-in with the existing industrial tool suite (Rubus-ICE). The experiments, that we performed, indicate that it is possible to achieve up to 4.48% improvement in schedulability when mixed messages are scheduled with offsets.
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extending schedulability Analysis of controller area network can for mixed periodic sporadic messages
Emerging Technologies and Factory Automation, 2011Co-Authors: Saad Mubeen, Jukka Mamturja, Mikael SjodinAbstract:The schedulability Analysis of Controller Area Network (CAN) developed by the research community is able to compute the response times of CAN messages that are queued for transmission periodically or sporadically. However, there are a few high-level protocols for CAN such as CANopen and Hagglunds Controller Area Network (HCAN) that support the transmission of mixed messages as well. A mixed message can be queued for transmission both periodically and sporadically. Thus, it does not exhibit a periodic activation pattern. The existing Analysis of CAN does not support the Analysis of mixed messages. We extend the existing Analysis to compute the response times of mixed messages. The Extended Analysis is generally applicable to any high level protocol for CAN that uses any combination of periodic, event and mixed (periodic/event) transmission of messages.
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extending response time Analysis of controller area network can with fifo queues for mixed messages
Emerging Technologies and Factory Automation, 2011Co-Authors: Saad Mubeen, Jukka Mamturja, Mikael SjodinAbstract:Existing response-time Analysis for Controller Area Network (CAN) messages in networks where some nodes implement FIFO queues while others implement priority queues, assumes that at every node, CAN messages are queued for transmission periodically or sporadically. However, there are a few high level protocols for CAN such as CANopen and Hagglunds Controller Area Network (HCAN) that support the transmission of mixed messages as well. A mixed message can be queued for transmission both periodically and sporadically. The existing Analysis of CAN with FIFO queues does not support the Analysis of mixed messages. We extend the existing response-time Analysis of mixed-type CAN messages. The Extended Analysis can compute the response-times of mixed (periodic/ sporadic) messages in the CAN network where some nodes use FIFO queues while others use priority queues.
S Scopel - One of the best experts on this subject based on the ideXlab platform.
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effect of the galactic halo modeling on the dama nai annual modulation result an Extended Analysis of the data for wimps with a purely spin independent coupling
Physical Review D, 2002Co-Authors: P Belli, R Cerulli, N Fornengo, S ScopelAbstract:The DAMA-NaI Collaboration has observed a $4\ensuremath{\sigma}$ C.L. model-independent effect investigating the annual modulation signature in the counting rate of an NaI(Tl) setup (total exposure of 57986 kg day) and the implications of this effect have been studied under different model-dependent assumptions. In this paper we extend one of the previous analyses, the case of a WIMP with a purely spin-independent coupling, by discussing in detail the implications on the results of the uncertainties on the dark matter galactic velocity distribution. We study in a systematic way possible departures from the isothermal sphere model, which is the parametrization usually adopted to describe the halo. We specifically consider modifications arising from various matter density profiles, effects due to anisotropies of the velocity dispersion tensor and rotation of the galactic halo. The hypothesis of WIMP annual modulation, already favored in the previous Analysis using an isothermal sphere, is confirmed in all the investigated scenarios, and the effects of the different halo models on the determination of the allowed maximum-likelihood region in the WIMP mass and WIMP-nucleon cross section are derived and discussed.
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effect of the galactic halo modeling on the dama nai annual modulation result an Extended Analysis of the data for weakly interacting massive particles with a purely spin independent coupling
Physical Review D, 2002Co-Authors: P Belli, R Cerulli, N Fornengo, S ScopelAbstract:The DAMA/NaI Collaboration has observed a 4-sigma C.L. model independent effect investigating the annual modulation signature in the counting rate of an NaI(Tl) set-up (total exposure of 57986 kg day) and the implications of this effect have been studied under different model-dependent assumptions. In this paper we extend one of the previous analyses, the case of a WIMP with a purely spin-independent coupling, by discussing in detail the implications on the results of the uncertainties on the dark matter galactic velocity distribution. We study in a systematic way possible departures from the isothermal sphere model, which is the parameterization usually adopted to describe the halo. We specifically consider modifications arising from various matter density profiles, effects due to anisotropies of the velocity dispersion tensor and rotation of the galactic halo. The hypothesis of WIMP annual modulation, already favoured in the previous Analysis using an isothermal sphere, is confirmed in all the investigated scenarios, and the effects of the different halo models on the determination of the allowed maximum-likelihood region in the WIMP mass and WIMP-nucleon cross-section are derived and discussed.
Michael Scott Matejek - One of the best experts on this subject based on the ideXlab platform.
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software holography interferometric data Analysis for the challenges of next generation observatories
Monthly Notices of the Royal Astronomical Society, 2009Co-Authors: M F Morales, Michael Scott MatejekAbstract:Next generation radio observatories such as the Murchison Widefield Array (MWA), the Long Wavelength Array (LWA), the LOw Frequency ARray (LOFAR), the Combined Array for Research Millimeter-wave Astronomy (CARMA) and the Square Kilometer Array (SKA) provide a number of challenges for interferometric data Analysis. These challenges include heterogeneous arrays, direction-dependent instrumental gain, and refractive and scintillating atmospheric conditions. From the Analysis perspective, this means that calibration solutions cannot be described using a single complex gain per antenna. In this paper, we use the optimal map-making formalism developed for cosmic microwave background analyses to extend traditional interferometric radio Analysis techniques - removing the assumption of a single complex gain per antenna and allowing more complete descriptions of the instrumental and atmospheric conditions. Due to the similarity with holographic mapping of radio antenna surfaces, we call this Extended Analysis approach software holography. The resulting Analysis algorithms are computationally efficient, unbiased and optimally sensitive. We show how software holography can be used to solve some of the challenges of next generation observations, and how more familiar Analysis techniques can be derived as limiting cases.
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software holography interferometric data Analysis for the challenges of next generation observatories
arXiv: Astrophysics, 2008Co-Authors: M F Morales, Michael Scott MatejekAbstract:Next generation radio observatories such as the MWA, LWA, LOFAR, CARMA and SKA provide a number of challenges for interferometric data Analysis. These challenges include heterogeneous arrays, direction-dependent instrumental gain, and refractive and scintillating atmospheric conditions. From the Analysis perspective, this means that calibration solutions can not be described using a single complex gain per antenna. In this paper we use the optimal map-making formalism developed for CMB analyses to extend traditional interferometric radio Analysis techniques--removing the assumption of a single complex gain per antenna and allowing more complete descriptions of the instrumental and atmospheric conditions. Due to the similarity with holographic mapping of radio antenna surfaces, we call this Extended Analysis approach software holography. The resulting Analysis algorithms are computationally efficient, unbiased, and optimally sensitive. We show how software holography can be used to solve some of the challenges of next generation observations, and how more familiar Analysis techniques can be derived as limiting cases.
Cory Koedel - One of the best experts on this subject based on the ideXlab platform.
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does student sorting invalidate value added models of teacher effectiveness an Extended Analysis of the rothstein critique
Education Finance and Policy, 2011Co-Authors: Cory Koedel, Julian R BettsAbstract:Value-added modeling continues to gain traction as a tool for measuring teacher performance. However, recent research questions the validity of the value-added approach by showing that it does not mitigate student-teacher sorting bias (its presumed primary benefit). Our study explores this critique in more detail. Although we find that estimated teacher effects from some value-added models are severely biased, we also show that a sufficiently complex value-added model that evaluates teachers over multiple years reduces the sorting bias problem to statistical insignificance. One implication of our findings is that data from the first year or two of classroom teaching for novice teachers may be insufficient to make reliable judgments about quality. Overall, our results suggest that in some cases value-added modeling will continue to provide useful information about the effectiveness of educational inputs. © 2011 Association for Education Finance and Policy
-
does student sorting invalidate value added models of teacher effectiveness an Extended Analysis of the rothstein critique
Education Finance and Policy, 2011Co-Authors: Cory Koedel, Julian R BettsAbstract:Value-added modeling continues to gain traction as a tool for measuring teacher performance. However, recent research questions the validity of the value-added approach by showing that it does not mitigate studentteacher sorting bias (its presumed primary benefit). Our study explores this critique in more detail. Although we find that estimated teacher effects from some valueadded models are severely biased, we also show that a sufficiently complex value-added model that evaluates teachers over multiple years reduces the sorting bias problem to statistical insignificance. One implication of our findings is that data from the first year or two of classroom teaching for novice teachers may be insufficient to make reliable judgments about quality. Overall, our results suggest that in some cases value-added modeling will continue to provide useful information about the effectiveness of educational inputs.
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does student sorting invalidate value added models of teacher effectiveness an Extended Analysis of the rothstein critique
Research Papers in Economics, 2009Co-Authors: Cory Koedel, Julian R BettsAbstract:Value-added modeling continues to gain traction as a tool for measuring teacher performance. However, recent research (Rothstein, 2009, forthcoming) questions the validity of the value-added approach by showing that it does not mitigate student-teacher sorting bias (its presumed primary benefit). Our study explores this critique in more detail. Although we find that estimated teacher effects from some value-added models are severely biased, we also show that a sufficiently complex value-added model that evaluates teachers over multiple years reduces the sorting-bias problem to statistical insignificance. One implication of our findings is that data from the first year or two of classroom teaching for novice teachers may be insufficient to make reliable judgments about quality. Overall, our results suggest that in some cases value-added modeling will continue to provide useful information about the effectiveness of educational inputs.
