Changes in standard of candidates taking the MRCP(UK) Part 1 examination, 1985 to 2002: Analysis of marker questions

The maintenance of standards is a problem for postgraduate medical examinations, particularly if they use norm-referencing as the sole method of standard setting. In each of its diets, the MRCP(UK) Part 1 Examination includes a number of marker questions, which are unchanged from their use in a previous diet. This paper describes two complementary studies of marker questions for 52 diets of the MRCP(UK) Part 1 Examination over the years 1985 to 2001 to assess whether standards have changed

How to Evaluate your Question Answering System Every Day and Still Get Real Work Done

In this paper, we report on Qaviar, an experimental automated evaluation system for question answering applications. The goal of our research was to find an automatically calculated measure that correlates well with human judges' assessment of answer correctness in the context of question answering tasks. Qaviar judges the response by computing recall against the stemmed content words in the human-generated answer key. It counts the answer correct if it exceeds agiven recall threshold. We determined that the answer correctness predicted by Qaviar agreed with the human 93% to 95% of the time. 41 question-answering systems were ranked by both Qaviar and human assessors, and these rankings correlated with a Kendall's Tau measure of 0.920, compared to a correlation of 0.956 between human assessors on the same data.Comment: 6 pages, 3 figures, to appear in Proceedings of the Second International Conference on Language Resources and Evaluation (LREC 2000

Copulas in finance and insurance

Copulas provide a potential useful modeling tool to represent the dependence structure among variables and to generate joint distributions by combining given marginal distributions. Simulations play a relevant role in finance and insurance. They are used to replicate efficient frontiers or extremal values, to price options, to estimate joint risks, and so on. Using copulas, it is easy to construct and simulate from multivariate distributions based on almost any choice of marginals and any type of dependence structure. In this paper we outline recent contributions of statistical modeling using copulas in finance and insurance. We review issues related to the notion of copulas, copula families, copula-based dynamic and static dependence structure, copulas and latent factor models and simulation of copulas. Finally, we outline hot topics in copulas with a special focus on model selection and goodness-of-fit testing

Statistical Approaches in GIS-Based Techniques for Sustainable Planning: Kayaçukuru Case

The purpose of this study is to make both a summary and additional descriptive and inferential statistical analyses for a completed thesis on "Sustainable/Environment Friendly Development Planning of Fethiye-Kayaçukuru Using GIS-Based Techniques" (M.Sc. in the Graduate School of Geodetic and Geographic Information Technologies, Middle East Technical University, Supervisor: Assoc.Prof.Dr. Oğuz Işık, September 2000, 214 pages). The statistical analyses explained in this paper comprise a part of the whole GIS-based techniques developed for a case study about Fethiye-Kayaçukuru Plain to explore the contributions of such an approach. In this respect, first, the study area, spatial and non-spatial data and the way they are handled are introduced. Then, the performed statistical descriptive and predictive analyses/models and their interpretations in the developed "loose-coupled" "decision/planning support system" are mentioned. Finally, the concluding remarks of the study are discussed emphasising the contributions of this approach in the sustainable/environment friendly development planning and in particular for the Plain. Keywords: Sustainable/environment friendly development, decision/planning support system, non-spatial and spatial statistical analyses, statistical testing, modelling.

On the density distribution across space: a probabilistic approach

This paper aims at providing a Bayesian parametric framework to tackle the accessibility problem across space in urban theory. Adopting continuous variables in a probabilistic setting we are able to associate with the distribution density to the Kendall's tau index and replicate the general issues related to the role of proximity in a more general context. In addition, by referring to the Beta and Gamma distribution, we are able to introduce a differentiation feature in each spatial unit without incurring in any a-priori definition of territorial units. We are also providing an empirical application of our theoretical setting to study the density distribution of the population across Massachusetts.Agglomerations, Bayesian inference, Distance, Gibbs sampling, Kendall's tau index, Population density.