33 research outputs found
Evaluation of marking of peer marking in oral presentation.
BACKGROUND: Peer marking is an important skill for students, helping them to understand the process of learning and assessment. This method is increasingly used in medical education, particularly in formative assessment. However, the use of peer marking in summative assessment is not widely adopted because many teachers are concerned about biased marking by students of their peers. OBJECTIVE: The aim of this study was to investigate whether marking of summative peer assessment can improve the reliability of peer marking. METHODS: In a retrospective analysis, the peer-marking results of a summative assessment of oral presentations of two cohorts of students were compared. One group of students was told that their peer marks would be assessed against a benchmark consisting of the average of examiner marks and that these scores together with the peer and examiner marks would form their final exam results. The other group of students were just informed that their final exam results would be determined based on the examiner and peer marks. RESULTS: Based on examiner marks, both groups of students performed similarly in their summative assessment, agreement between student markers was less consistent and more polar than the examiners. When compared with the examiners, students who were told that their peer marking would be scored were more generous markers (their average peer mark was 2.4 % points higher than the average examiner mark) while students who were not being scored on their marking were rather harsh markers (their average peer mark was 4.2 % points lower than the average examiner mark), with scoring of the top-performing students most affected. CONCLUSIONS: Marking of peer marking had a small effect on the marking conduct of students in summative assessment of oral presentation but possibly indicated a more balanced marking performance
Ultrathin initiated chemical vapor deposition polymer interfacial energy control for directed self-assembly hole-shrink applications
Single-step, spin-on process for high fidelity and selective deposition
Processes that enable selective deposition in thin films are desired for advanced patterning applications to reduce overlay demands, but conventional techniques are slow and limited in material scope. Here, we report a method that selectively deposits polymeric coatings on heterogeneous substrates (Cu/SiO2) using spin coating. Unlike traditional approaches that rely on surface pretreatments, herein, selectivity is induced by polymer design that promotes preferential dewetting from one substrate material and uniform wetting on the other. As evidenced by studies with homogeneous surfaces, poly(acrylates) containing semifluorinated pendant groups satisfy this criterion and spontaneously dewet from SiO2 but form continuous films on Cu. When spin coated onto Cu/SiO2 line–space patterns, these semifluorinated polymers selectively coat only the Cu lines without any pre- or postprocessing. Rational design rules have been elucidated that anticipate regimes of selective deposition by correlating the droplet size of dewetted features on homogeneous SiO2 with the dimensions of heterogeneous Cu/SiO2 patterns. The universality of this unique strategy is demonstrated across a library of polymers with varying molecular weights and monomer structures, providing significant advances arising from the simplicity and rapidity of spin coating. For 10–40 μm full pitch features, the entire deposition procedure involves a single step and is complete in under 1 min
Rapid and selective deposition of patterned thin films on heterogeneous substrates via spin coating
The selective deposition of polymer thin films can be achieved via spin coating by manipulating interfacial interactions. While this "spin dewetting" approach sometimes generates spatial localization on topographic and chemical patterns, the connection between material selection, process parameters, and resulting film characteristics remains poorly understood. Here, we demonstrate that accurate control over these parameters allows incomplete trichlorosilane self-assembled monolayers (SAMs) to induce spin dewetting on both homogeneous (SiO) and heterogeneous (Cu/SiO or TiN/SiO) surfaces. Glassy polymers undergo a sharp transition from uniform wetting to complete dewetting depending on spin speed, solution concentration, polymer molecular weight, and SAM chemistry. Under optimal conditions, spin dewetting on line-space patterns results in the selective deposition of polymer over regions not functionalized with SAM. The insights described herein clarify the importance of different variables involved in spin dewetting and provide access to a versatile strategy for patterning polymeric thin films
Sociodemographic and psychosocial factors in childhood as predictors of adult mortality.
Classroom BRIDGE: using collaborative public and desktop timelines to support activity awareness
Classroom BRIDGE supports activity awareness by facilitating planning and goal revision in collaborative, project-based middle school science. It integrates largescreen and desktop views of project times to support incidental creation of awareness information through routine document transactions, integrated presentation of awareness information as part of workspace views, and public access to subgroup activity. It demonstrates and develops an object replication approach to integrating synchronous and asynchronous distributed work for a platform incorporating both desktop and large-screen devices. This paper describes an implementation of these concepts with preliminary evaluation data, using timelinebased user interfaces