27,495 research outputs found
Book reviews: On commodifying intangibles
Book reviews of: 1) James Boyle, Shamans, Software, and Spleens: Law and the Construction of the Information Society. Cambridge: Harvard University Press, 1996. Pp. xvi, 270. 15.95 (paper). 2) Margaret Jane Radin, Contested Commodities. Cambridge: Harvard University Press, 1996. Pp. xiv, 279. $35.00
Validity of very short answer versus single best answer questions for undergraduate assessment
Background Single Best Answer (SBA) questions are widely used in undergraduate and postgraduate medical examinations. Selection of the correct answer in SBA questions may be subject to cueing and therefore might not test the student’s knowledge. In contrast to this artificial construct, doctors are ultimately required to perform in a real-life setting that does not offer a list of choices. This professional competence can be tested using Short Answer Questions (SAQs), where the student writes the correct answer without prompting from the question. However, SAQs cannot easily be machine marked and are therefore not feasible as an instrument for testing a representative sample of the curriculum for a large number of candidates. We hypothesised that a novel assessment instrument consisting of very short answer (VSA) questions is a superior test of knowledge than assessment by SBA. Methods We conducted a prospective pilot study on one cohort of 266 medical students sitting a formative examination. All students were assessed by both a novel assessment instrument consisting of VSAs and by SBA questions. Both instruments tested the same knowledge base. Using the filter function of Microsoft Excel, the range of answers provided for each VSA question was reviewed and correct answers accepted in less than two minutes. Examination results were compared between the two methods of assessment. Results Students scored more highly in all fifteen SBA questions than in the VSA question format, despite both examinations requiring the same knowledge base. Conclusions Valid assessment of undergraduate and postgraduate knowledge can be improved by the use of VSA questions. Such an approach will test nascent physician ability rather than ability to pass exams
Getting the most out of a post-column EELS spectrometer on a TEM/STEM by optimising the optical coupling
Ray tracing is used to find improved set-ups of the projector system of a JEOL ARM 200CF TEM/STEM for use in coupling it to a Gatan 965 Quantum ER EELS system and to explain their performance. The system has a probe aberration corrector but no image corrector. With the latter, the problem would be more challenging. The agreement between the calculated performance and that found experimentally is excellent. At 200kV and using the 2.5mm Quantum entrance aperture, the energy range over which the collection angle changes by a maximum of 5% from that at zero loss has been increased from 1.2keV to 4.7keV. At lower accelerating voltages, these energy ranges are lower e.g. at 80kV they are 0.5keV and 2.0keV respectively. The key factors giving the improvement are an increase in the energy-loss at which the projector cross-over goes to infinity and a reduction of the combination aberrations that occur in a lens stack. As well as improving the energy-loss range, the new set-ups reduce spectrum artefacts and minimise the motion of the diffraction pattern at low STEM magnification for electrons that have lost energy. Even if making the pivot points conjugate with the film plane gives no motion for zero-loss electrons, there will be motion for those electrons that have lost energy, leading to a false sense of security when performing spectrum imaging at low magnifications. De-scanning of the probe after the objective lens is a better way of dealing with this problem
Greenbug: a hybrid web-inspector, debugger and design editor for greenstone
In this paper we present Greenbug: a hybrid web inspector, debugger and design editor developed for use with the open source digital library software Greenstone 3. Inspired by the web development tool Firebug, Greenbug is more tightly coupled with the underlying (digital library) server than that provided by Firebug; for example, Greenbug has a fine-grained knowledge of the connection between the underlying file system and the rendered web content, and also provides the ability to commit any changes made through the web interface back to the underlying file system. Moreover, because web page production in Greenstone 3 is the result of an XSLT processing pipeline, the necessarily well-formed hierarchical XML content can be manipulated into a graphical representation, which can then be manipulated directly through a visual interface supplied by Greenbug. We showcase the interface in use, provide a brief overview of implementation details, and conclude with a discussion on how the approach can be adapted to other XSLT transformation-based content management systems, such as DSpace
Clinical practice guidelines for the management of atypical haemolytic uraemic syndrome in the United Kingdom
- …
