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In this article, Heather C. Hill and Pam Grossman discuss the current focus on using teacher observation instruments as part of new teacher evaluation systems being considered and implemented by states and districts. They argue that if these teacher observation instruments are to achieve the goal of supporting teachers in improving instructional practice, they must be subject-specific, involve content experts in the process of observation, and provide information that is both accurate and useful for teachers. They discuss the instruments themselves, raters and system design, and timing of and feedback from the observations. They conclude by outlining the challenges that policy makers face in designing observation systems that will work to improve instructional practice at scale.

Poor program implementation constitutes one explanation for null results in trials of educational interventions. For this reason, researchers often collect data about implementation fidelity when conducting such trials. In this article, we document whether and how researchers report and measure program fidelity in recent cluster-randomized trials. We then create two measures—one describing the level of fidelity reported by authors and another describing whether the study reports null results—and examine the correspondence between the two. We also explore whether fidelity is influenced by study size, type of fidelity measured and reported, and features of the intervention. We find that as expected, fidelity level relates to student outcomes; we also find that the presence of new curriculum materials positively predicts fidelity level.

Commentaries regarding appropriate methods for researching professional development have been a frequent topic in recent issues of Educational Researcher as well as other venues. In this article, the authors extend this discussion by observing that randomized trials of specific professional development programs have not enhanced our knowledge of effective program characteristics, leaving practitioners without guidance with regard to best practices. In response, the authors propose that scholars should execute more rigorous comparisons of professional development designs at the initial stages of program development and use information derived from these studies to build a professional knowledge base. The authors illustrate with examples of both a proposed study and reviews of evidence on key questions in the literature.

Control of the optical properties of matter on ultrashort timescales is of both fundamental interest and central importance for applications in photonics. It is desirable to achieve pronounced changes over a broad spectral range using the least possible amount of material. Here, we demonstrate a dramatic change over a spectral range of hundreds of meV on the femtosecond timescale in the optical response of atomically thin two-dimensional crystals of the transition-metal dichalcogenide WS 2 following excitation by intense optical pump pulses. Our findings reveal the role of extremely strong Coulomb interactions. At the direct gap, we observe a Mott transition from excitonic states to free carriers, accompanied by a giant bandgap renormalization of approximately 500 meV and the development of population inversion. Atomically thin layers of transition metal dichalcogenides are shown to exhibit a disappearance of strong excitonic absorption along with population inversion at the direct gap over a spectral range of hundreds of meV after pulsed photoexcitation.

Animal documentary films such as Blackfish , considered nonfiction accounts of reality, nonetheless use rhetorical devices to engage viewers and shape their emotional experience for maximum effect. Such devices can also influence attitudes and alter behavior. In animal documentaries, anthropomorphic impressions of the animals by audiences are key. Using general population samples in the US, three online experiments assessed the influence of background music and narrative setting on how viewers emotionally appraised the emotional state of a killer whale ( Orcinus orca ) and subsequently donated to causes affiliated with killer whales. While happy music led to perceptions of a happy whale, sad music led to perceptions of a sad whale. mediation analyses showed that these perceptions indirectly influence donation behavior, via beliefs about the killer whale’s welfare and wellbeing. Analyses also indicated that the highest donation amounts towards killer whales were elicited from footage depicting a killer whale in the wild, with sad background music. These findings highlight the potential power that animal and nature documentaries have over viewers, which, when combined with human tendencies toward anthropomorphism, can have significant influence on conservation attitudes and behavior.

Both scholars and professional standards identify teachers' knowledge of students as important to promoting effective instruction and student learning. Prior research investigates two such types of knowledge: knowledge of student thinking and teacher accuracy in predicting student performance on cognitive assessments. However, the field presents weak evidence regarding whether these constructs are amenable to accurate measurement and whether such knowledge relates to instruction and student outcomes. Without this evidence, it is difficult to assess the relevance of this form of teacher knowledge. In this article, evidence from 284 teachers suggests that accuracy can be adequately measured and relates to instruction and student outcomes. Knowledge of student misconceptions proved more difficult to measure, yet still predicted student outcomes in one model.

The ability to control the size of the electronic bandgap is an integral part of solid-state technology. Atomically thin two-dimensional crystals offer a new approach for tuning the energies of the electronic states based on the unusual strength of the Coulomb interaction in these materials and its environmental sensitivity. Here, we show that by engineering the surrounding dielectric environment, one can tune the electronic bandgap and the exciton binding energy in monolayers of WS 2 and WSe 2 by hundreds of meV. We exploit this behaviour to present an in-plane dielectric heterostructure with a spatially dependent bandgap, as an initial step towards the creation of diverse lateral junctions with nanoscale resolution. Electronic bandgap tuning in semiconductors enables key functionalities in solid-state devices. Here, the authors present a strategy to control the bandgap of atomically thin WS 2 and WSe 2 semiconductors via manipulation of the surrounding dielectric environment rather than by modifications of the materials themselves.

Recent decades have seen increases in the variability of family income, tepid income growth rates for all but the richest families, and widening income inequality. These trends are concerning for child well-being, given the importance of income to parental investments and parenting practices. Growing evidence suggests that a high level of change is disruptive to family processes and that chronic stress affects physiology as well as psychology. This study used the Panel Study of Income Dynamics Child Development Supplement to estimate associations between three dimensions of childhood income dynamics—level, variability, and trend—and child achievement and behavior. After income level was controlled for, income variability during childhood was not associated with child achievement or behavior, but an increasing five-year trend in income-to-needs was modestly beneficial to behavior measures. Subgroup analysis suggests some adverse effects of income variability and trend on reading and behavior for non-White children but no clear patterns by child’s age or family income or wealth levels.

We present results from a meta-analysis of 95 experimental and quasi-experimental pre-K–12 science, technology, engineering, and mathematics (STEM) professional development and curriculum programs, seeking to understand what content, activities, and formats relate to stronger student outcomes. Across rigorously conducted studies, we found an average weighted impact estimate of +0.21 standard deviations. Programs saw stronger outcomes when they helped teachers learn to use curriculum materials; focused on improving teachers’ content knowledge, pedagogical content knowledge, and/or understanding of how students learn; incorporated summer workshops; and included teacher meetings to troubleshoot and discuss classroom implementation. We discuss implications for policy and practice.

Value-added models have become popular in research and pay-for-performance plans. While scholars have focused attention on some aspects of their validity (e.g., scoring procedures), others have received less scrutiny. This article focuses on the extent to which value-added scores correspond to other indicators of teacher and teaching quality. The authors compared 24 middle school mathematics teachers' value-added scores, derived from a large (N = 222) district data set, to survey- and observation-based indicators of teacher quality, instruction, and student characteristics. This analysis found teachers' value-added scores correlated not only with their mathematical knowledge and quality of instruction but also with the population of students they teach. Case studies illustrate problems that might arise in using value-added scores in pay-for-performance plans.