257 research outputs found
Item-writing Rules: Collective Wisdom
In student assessment, teachers place the greatest weight on tests they have constructed themselves and have an equally great interest in the quality of those tests. To increase the validity of teacher-made tests, many item-writing rules-of-thumb are available in the literature, but few rules have been tested experimentally. In light of the paucity of empirical studies, the validity of any given guideline might best be established by relying on experts. This study analyzed twenty classroom assessment textbooks to identify a consensus list of item-writing rules. Forty rules for which there was agreement among textbook authors are presented. The rules address four different validity concerns-potentially confusing wording or ambiguous requirements, the problem of guessing, test-taking efficiency, and controlling for testwiseness
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Defining Authentic Classroom Assessment
A commonly advocated best practice for classroom assessment is to make the assessments authentic. Authentic is often used as meaning the mirroring of real-world tasks or expectations. There is no consensus, however, in the actual definition of the term or the characteristics of an authentic classroom assessment. Sometimes, the realistic component is not even an element of a researcher\u27s or practitioner\u27s meaning. This study presents a conceptual analysis of authentic as it is used in educational research and training to describe an approach to classroom assessment. Nine distinct components or dimensions of authenticity are identified and only one of those is the realistic nature of the assessment. Accessed 54,632 times on https://pareonline.net from January 12, 2012 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right
Balanced Literacy in an Urban School District
This is the authors' accepted manuscript, post peer-review. The publisher's official version is available electronically from: http://dx.doi.org/10.3200/JOER.98.5.272-280.Balanced literacy is a philosophical orientation that assumes that reading and writing
achievement are developed through instruction and support in multiple environments using
various approaches that differ by level of teacher support and child control. This study
describes one urban school district’s real-world attempt to create a balance between reading
and writing, between teacher-directed and student-centered activities, and between skillsbased
and meaning based approaches to literacy instruction. A triangulation strategy using
multiple methods of data collection, including classroom observations, inventories of the
physical environment of classrooms and school buildings, teacher surveys, and student
interviews, was used to measure balanced literacy components. Results suggest that teacherdirected
instruction, a fundamental aspect of balanced literacy, was implemented less often
than either independent reading or writing activities. Teachers appeared to be allocating
instructional time as directed by district administrators, and they were implementing
components of a balanced literacy program. Additionally, most school buildings had a physical
environment supportive of balanced literacy. However, the amount of time devoted to
instruction and modeling effective reading and writing strategies seemed too limited for a
group of students with poorly developed reading and writing skills
Lability of DOC transported by Alaskan rivers to the Arctic Ocean
Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 35 (2008): L03402, doi:10.1029/2007GL032837.Arctic rivers transport huge quantities of dissolved organic carbon (DOC) to the Arctic Ocean. The prevailing paradigm is that DOC in arctic rivers is refractory and therefore of little significance for the biogeochemistry of the Arctic Ocean. We show that there is substantial seasonal variability in the lability of DOC transported by Alaskan rivers to the Arctic Ocean: little DOC is lost during incubations of samples collected during summer, but substantial losses (20–40%) occur during incubations of samples collected during the spring freshet when the majority of the annual DOC flux occurs. We speculate that restricting sampling to summer may have biased past studies. If so, then fluvial inputs of DOC to the Arctic Ocean may have a much larger influence on coastal ocean biogeochemistry than previously realized, and reconsideration of the role of terrigenous DOC on carbon, microbial, and food-web dynamics on the arctic shelf will be warranted.This material is based on work supported by
the National Science Foundation under grant numbers OPP-0436106, OPP-
0519840, and EAR-0403962, and is a contribution to the Study of
Environmental Arctic Change (SEARCH)
The Microstructure of a U.S. Treasury ECN: The Brokertec Platform
This paper assesses the microstructure of the U.S. Treasury securities market, using newly available tick data from the BrokerTec electronic trading platform. Examining trading activity, bid-ask spreads, and depth for on-the-run two-, three-, five-, ten-, and thirty-year Treasury securities, we find that market liquidity is greater than that found in earlier studies that use data only from voice-assisted brokers. We find that the price effect of trades on BrokerTec is quite small and is even smaller once order-book information is considered. Moreover, order-book information itself is shown to affect prices. We also explore a novel feature of BrokerTec - the ability to enter hidden ('iceberg') orders - and find that, as predicted by theory, such orders are more common when price volatility is higher
Upper limits on the strength of periodic gravitational waves from PSR J1939+2134
The first science run of the LIGO and GEO gravitational wave detectors
presented the opportunity to test methods of searching for gravitational waves
from known pulsars. Here we present new direct upper limits on the strength of
waves from the pulsar PSR J1939+2134 using two independent analysis methods,
one in the frequency domain using frequentist statistics and one in the time
domain using Bayesian inference. Both methods show that the strain amplitude at
Earth from this pulsar is less than a few times .Comment: 7 pages, 1 figure, to appear in the Proceedings of the 5th Edoardo
Amaldi Conference on Gravitational Waves, Tirrenia, Pisa, Italy, 6-11 July
200
Improving the sensitivity to gravitational-wave sources by modifying the input-output optics of advanced interferometers
We study frequency dependent (FD) input-output schemes for signal-recycling
interferometers, the baseline design of Advanced LIGO and the current
configuration of GEO 600. Complementary to a recent proposal by Harms et al. to
use FD input squeezing and ordinary homodyne detection, we explore a scheme
which uses ordinary squeezed vacuum, but FD readout. Both schemes, which are
sub-optimal among all possible input-output schemes, provide a global noise
suppression by the power squeeze factor, while being realizable by using
detuned Fabry-Perot cavities as input/output filters. At high frequencies, the
two schemes are shown to be equivalent, while at low frequencies our scheme
gives better performance than that of Harms et al., and is nearly fully
optimal. We then study the sensitivity improvement achievable by these schemes
in Advanced LIGO era (with 30-m filter cavities and current estimates of
filter-mirror losses and thermal noise), for neutron star binary inspirals, and
for narrowband GW sources such as low-mass X-ray binaries and known radio
pulsars. Optical losses are shown to be a major obstacle for the actual
implementation of these techniques in Advanced LIGO. On time scales of
third-generation interferometers, like EURO/LIGO-III (~2012), with
kilometer-scale filter cavities, a signal-recycling interferometer with the FD
readout scheme explored in this paper can have performances comparable to
existing proposals. [abridged]Comment: Figs. 9 and 12 corrected; Appendix added for narrowband data analysi
Search for gravitational wave bursts in LIGO's third science run
We report on a search for gravitational wave bursts in data from the three
LIGO interferometric detectors during their third science run. The search
targets subsecond bursts in the frequency range 100-1100 Hz for which no
waveform model is assumed, and has a sensitivity in terms of the
root-sum-square (rss) strain amplitude of hrss ~ 10^{-20} / sqrt(Hz). No
gravitational wave signals were detected in the 8 days of analyzed data.Comment: 12 pages, 6 figures. Amaldi-6 conference proceedings to be published
in Classical and Quantum Gravit
Crafting organization
The recent shift in attention away from organization studies as science has allowed for consideration of new ways of thinking about both organization and organizing and has led to several recent attempts to \u27bring down\u27 organizational theorizing. In this paper, we extend calls for organization to be represented as a creative process by considering organization as craft. Organizational craft, we argue, is attractive, accessible, malleable, reproducible, and marketable. It is also a tangible way of considering organization studies with irreverence. We draw on the hierarchy of distinctions among fine art, decorative art, and craft to suggest that understanding the organization of craft assists in complicating our understanding of marginality. We illustrate our argument by drawing on the case of a contemporary Australian craftworks and marketplace known initially as the Meat Market Craft Centre (\u27MMCC\u27) and then, until its recent closure, as Metro! ‡ Stella Minahan was a board member and then the Chief Executive Officer of the Metro! Craft Centre.<br /
Quantum state preparation and macroscopic entanglement in gravitational-wave detectors
Long-baseline laser-interferometer gravitational-wave detectors are operating
at a factor of 10 (in amplitude) above the standard quantum limit (SQL) within
a broad frequency band. Such a low classical noise budget has already allowed
the creation of a controlled 2.7 kg macroscopic oscillator with an effective
eigenfrequency of 150 Hz and an occupation number of 200. This result, along
with the prospect for further improvements, heralds the new possibility of
experimentally probing macroscopic quantum mechanics (MQM) - quantum mechanical
behavior of objects in the realm of everyday experience - using
gravitational-wave detectors. In this paper, we provide the mathematical
foundation for the first step of a MQM experiment: the preparation of a
macroscopic test mass into a nearly minimum-Heisenberg-limited Gaussian quantum
state, which is possible if the interferometer's classical noise beats the SQL
in a broad frequency band. Our formalism, based on Wiener filtering, allows a
straightforward conversion from the classical noise budget of a laser
interferometer, in terms of noise spectra, into the strategy for quantum state
preparation, and the quality of the prepared state. Using this formalism, we
consider how Gaussian entanglement can be built among two macroscopic test
masses, and the performance of the planned Advanced LIGO interferometers in
quantum-state preparation
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