Biomedical subjects

Scott Elliott

Publications and source records attributed to Scott Elliott.

4 recordsLinked to original sources

PubMed2004

Computer-based testing: initial report of extensive use in a medical school curriculum.

BACKGROUND: Computer-based digital technology offers many opportunities in medical education. One type of digital technology, computer-based testing (CBT), has potentially wide application in undergraduate, graduate, and continuing medical education. DESCRIPTION: This articles describes the development of CBT in an undergraduate medical curriculum. EVALUATION: An early step in evaluating CBT is to be sure that the exam format is measuring the examinees' knowledge and not their comfort level or confidence with the technology. It is, therefore, important that the CBT reproduce or accommodate traditional test-taking behavior. CBT also provides for a number of enhancements not easily achieved with traditional paper-and-pencil exams. These include easier control and editing of exam items, better incorporation of testing into the learning environment using specific feedback, and enhancing the questions by incorporating multimedia. CBT does present some unique challenges in testing security, and this article discusses the approach to the security issues. In addition, before initiating CBT into a medical curriculum, the institution must understand the technical and infrastructure requirements for CBT. CONCLUSIONS: By providing a 5-year experience with CBT in the medical curriculum, this article hopes to facilitate discussions among medical educators in its appropriate application and evaluation.

Clinical Competence↗

PubMed2004

Recommendations for assigning weights to component tests to derive an overall grade.

BACKGROUND: Performance-based assessments are often not reliable enough to be used as the sole method for determining a grade. PURPOSE: Using more than 1 assessment format has several advantages and can improve the quality of the information used to calculate course grades. To achieve a valid and reliable total score representing a combination of multiple assessment formats requires appropriate weighting procedures. METHODS: The classical test theory rationale and methodology for appropriately weighting in-course assessments is presented. Two reliablility-related equations are used to make decisions about weighting for a computerized performance assessment and a pattern recognition multiple-choice exam. RESULTS: Using the equations presented, the outcomes of various weighting scenarios are graphically presented. This technique produced weights that allow the instructor to obtain acceptable reliability while retaining a substantial emphasis on performance assessment. CONCLUSION: The weights assigned to component tests used to derive a total score have important reliability and validity implications. Course instructors need to consider both empirical reliability and logical validity evidence in determining component weights. When used in conjunction with classical methods, objectively scored item formats can augment performance assessments and enhance overall validity and reliability.

Computer Simulation↗

PubMed2003

Global eddy permitting simulations of surface ocean nitrogen, iron, sulfur cycling.

The geocycles of N, Fe and S in the ocean are tightly coupled and together exert strong influence on biogeochemistry of the earth system. We investigate this interaction by inserting macro-micronutrient cycling into a high resolution ocean model that realistically represents the general circulation. Simulated chlorophyll distributions reproduce many features of satellite-based measurements of ocean color. Meridional sections through model results and seasonally averaged SeaWiFS data agree reasonably well, both in the oligotrophic gyres and along fronts. Discrepancies are associated in many cases with shelf, ridge or island effects. Dimethyl sulfide peaks and their chlorophyll correlations are similar to those obtained on major oceanographic expeditions. Lack of strong regional relationships between the sulfide and phytoplankton may be partly explained by correspondence between time constants for production and for the traversal of mesoscale transport features. In general the eddies and filaments of tropical instability waves are well represented, including the onset of the 1997-1998 El Niño. North-south shifts of the transition zone chlorophyll front appear prominently in the results.

Animals↗

PubMed2002

Megacities and the environment.

The world's 25 largest cities comprise only 4% of the global population, but they have substantial impacts on the environment at multiple scales. Here we review what is known of the biogeochemistry of these megacities. Climatic, demographic, and economic data show no patterns across cities, save that wealthier cities have lower growth rates. The flows of water, fuels, construction materials, and food are examined where data are available. Water, which by mass dwarfs the other inputs, is not retained in urban systems, whereas construction materials and food predominate in the urban infrastructure and the waste stream. Fuels are transformed into chemical wastes that have the most far-reaching and global impacts. The effects of megacity resource consumption on geologic, hydrologic, atmospheric, and ecological processes are explored at local, regional, and global scales. We put forth the concepts of urban metabolism and urban succession as organizing concepts for data collection, analysis, and synthesis on urban systems. We conclude that megacities are not the final stage of urban evolution; rather, the climax of urban development will occur at a global scale when human society is at steady state with resource supply rates.

Animals↗