What is your teacher rubric? Extracting teachers’ assessment constructs

Rubrics not only document the scales and criteria of what is assessed, but can also represent the assessment construct of the developer. Rubrics display the key assessment criteria, and the simplicity or complexity of the rubric can illustrate the meaning associated with the score. For this study, five experienced teachers developed a rubric for an EFL (English as a Foreign Language) descriptive writing task. Results show that even for the same task, teachers developed different formats and styles of rubric with both similar and different criteria. The teacher rubrics were analyzed for assessment criteria, rubric type and scale type. Findings illustrate that in terms of criteria, all teacher rubrics had five areas in common: comprehension, paragraph structure, sentence structure, vocabulary, and grammar. The criteria that varied were mechanics, length, task completion, and self-correction. Rubric style and scales also were different among teachers. Teachers who valued global concerns (i.e., comprehension) in writing designed more general holistic rubrics, while teachers who focused more on sentence-level concerns (i.e., grammar) developed analytic rubrics with more details. The assessment construct of the teacher was shown in the rubric through assessment criteria, rubric style, and scale. Accessed 7,170 times on https://pareonline.net from March 20, 2015 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Approach to accurately measuring the speed of optical precursors

Precursors can serve as a bound on the speed of information with dispersive medium. We propose a method to identify the speed of optical precursors using polarization-based interference in a solid-state device, which can bound the accuracy of the precursors' speed to less than $10^{-4}$ with conventional experimental conditions. Our proposal may have important implications for optical communications and fast information processing.Comment: 4 pages, 4 figure

Rydberg-atom graphs for quadratic unconstrained binary optimization problems

There is a growing interest in harnessing the potential of the Rydberg-atom system to address complex combinatorial optimization challenges. Here we present an experimental demonstration of how the quadratic unconstrained binary optimization (QUBO) problem can be effectively addressed using Rydberg-atom graphs. The Rydberg-atom graphs are configurations of neutral atoms organized into mathematical graphs, facilitated by programmable optical tweezers, and designed to exhibit many-body ground states that correspond to the maximum independent set (MIS) of their respective graphs. We have developed four elementary Rydberg-atom subgraph components, not only to eliminate the need of local control but also to be robust against interatomic distance errors, while serving as the building blocks sufficient for formulating generic QUBO graphs. To validate the feasibility of our approach, we have conducted a series of Rydberg-atom experiments selected to demonstrate proof-of-concept operations of these building blocks. These experiments illustrate how these components can be used to programmatically encode the QUBO problems to Rydberg-atom graphs and, by measuring their many-body ground states, how their QUBO solutions are determined subsequently.Comment: 13 pages, 6 figure

Size-regulated group separation of CoFe2O4 nanoparticles using centrifuge and their magnetic resonance contrast properties

Magnetic nanoparticle (MNP)-based magnetic resonance imaging (MRI) contrast agents (CAs) have been the subject of extensive research over recent decades. The particle size of MNPs varies widely and is known to influence their physicochemical and pharmacokinetic properties. There are two commonly used methods for synthesizing MNPs, organometallic and aqueous solution coprecipitation. The former has the advantage of being able to control the particle size more effectively; however, the resulting particles require a hydrophilic coating in order to be rendered water soluble. The MNPs produced using the latter method are intrinsically water soluble, but they have a relatively wide particle size distribution. Size-controlled water-soluble MNPs have great potential as MRI CAs and in cell sorting and labeling applications. In the present study, we synthesized CoFe(2)O(4) MNPs using an aqueous solution coprecipitation method. The MNPs were subsequently separated into four groups depending on size, by the use of centrifugation at different speeds. The crystal shapes and size distributions of the particles in the four groups were measured and confirmed by transmission electron microscopy and dynamic light scattering. Using X-ray diffraction analysis, the MNPs were found to have an inverse spinel structure. Four MNP groups with well-selected semi-Gaussian-like diameter distributions were obtained, with measured T(2) relaxivities (r(2)) at 4.7 T and room temperature in the range of 60 to 300 mM(−1)s(−1), depending on the particle size. This size regulation method has great promise for applications that require homogeneous-sized MNPs made by an aqueous solution coprecipitation method. Any group of the CoFe(2)O(4) MNPs could be used as initial base cores of MRI T(2) CAs, with almost unique T(2) relaxivity owing to size regulation. The methodology reported here opens up many possibilities for biosensing applications and disease diagnosis. PACS: 75.75.Fk, 78.67.Bf, 61.46.D

Can precursors improve the transmission of energy at optical frequencies?

The recent interest in precursors has been fuelled by the possibility of using them for the efficient transmission of information through absorbing media at radio or optical frequencies. Here we demonstrate that the low attenuation experienced by the Brillouin precursor is attributed to the inherently low absorption of dispersive media near DC, a characteristic already exploited with communications systems using the extremely low frequency (ELF) band. Pulses, regardless of their temporal width and carrier frequency, always obey Beer's law as long as they propagate in the linear time invariant regime. We conclude with an FDTD simulation of the Maxwell–Bloch equations that shows how optical coherent bleaching effects, which take place in the linear time variant regime of the Lorentz oscillator model, can cause sustained deviations from Beer's law over relatively long distances of water

Perspectives of language assessment training for teachers and testing professionals

Even before the field of Language Testing emerged as an independent field in applied linguistics, language assessment courses had been taught in various forms and by different instructors. Currently, these courses are being taught by professionals who have majored in the area of Language Testing (LTs) but also by others who come from different majors (non-LTs). This study seeks to investigate the effect instructors bring in shaping the characteristics (i.e., content, structure) of language assessment courses and to what extent the student-teacher are satisfied with the course. To get the full picture, the characteristics and satisfaction of the courses are researched from 4 different lenses; instructors who teach the course (Language Testers vs. Non-Language Testers) and different grade levels of language student teachers (Adult vs. K-12) who have taken the course. A large scale on-line survey, in-depth follow-up phone interviews and syllabi document review have been done for the study. A total of 384 instructors and student teachers completed the on-line survey (instructors n=140, student-teachers n=244). Based on the survey results an in-depth phone interview has been conducted with 13 instructors from 5 different countries and 5 student- teachers. Survey findings show there are significant differences in the content of the course depending on the instructors??? background in six areas; test specifications, test theory, basic statistics, classroom assessment, rubric development, and test accommodation. Interview results confirm non-LTs are less confident in teaching technical assessment skills compared to LTs and have a tendency to focus on more classroom assessment issues. Student teachers are overall satisfied with the course but wanted more activities that were directly related to the course. The study ends by predicting the future of language assessment courses and why it is important for both LTs and non-LTs to communicate and work actively to develop a better course that fulfills the needs of the student teachers

Slow-light-induced interference with stacked optical precursors for square input pulses

We theoretically study the stacked optical transients generated from a series of square pulses passing through a cold atomic ensemble. Using the hybrid analysis and fast Fourier transform, we identify the stacked coherent transients [Europhys. Lett. 4, 47 (1987)] as optical precursors. With slow-light and electromagnetically induced transparency, we obtain nearly 700\% transmitted intensity at the transient spikes resulting from the interference between the delayed main field and the stacked optical precursors. (C) 2010 Optical Society of Americ

Proposed narrowband biphoton generation from an ensemble of solid-state quantum emitters

We explore a mechanism for producing time-frequency entangled photon pairs (termed a biphoton) from an ensemble of atom-like solid-state quantum emitters. Four distinct energy levels of the solid-state system render four spin-conserving optical transitions as observed in color centers. This feature opens up the possibility to generate a four-wave mixing biphoton based on an electromagnetic induced transparency (EIT) for long-coherence quantum communication as demonstrated in cold atomic systems. We propose a narrow EIT window below a lifetime-limited linewidth of a SiV− in diamond, assuming a few hundred MHz. Consequently, the EIT-induced narrowband guarantees biphoton coherence time to be at least a few tens of a nanosecond without a cavity. Assessing the criteria of solid-state parameters applicable to the existing biphoton model from cold atoms will accelerate solid-state biphoton source research. This study shows that a realization of negligible ground state dephasing of a solid-state sample will be a crucial step toward a solid-state biphoton generation for more than a 100 ns time scale with a subnatural atomic linewidth of a few MHz. © 2019 Optical Society of America