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Selection Techniques (selection + techniques)
Selected AbstractsFairness Reactions to Personnel Selection Techniques in Spain and PortugalINTERNATIONAL JOURNAL OF SELECTION AND ASSESSMENT, Issue 1-2 2004Silvia Moscoso This paper examines the reactions to personnel selection methods in Spain and Portugal using a sample composed of 125 and 104 students, respectively. The results found are very similar in both countries. The best rated and most favorable methods are interviews, résumés and work sample tests, while contacts, integrity tests and graphology were the least favorable ones. With regard to the process dimensions used, face validity and opportunity to perform are the most important bases for considering personnel techniques favorably. The results show some similarities with the ones found by Steiner and Gilliland (1996) in French and American samples. The similarities among the countries are examined and directions for future research are discussed. [source] Classification of GC-MS measurements of wines by combining data dimension reduction and variable selection techniquesJOURNAL OF CHEMOMETRICS, Issue 8 2008Davide Ballabio Abstract Different classification methods (Partial Least Squares Discriminant Analysis, Extended Canonical Variates Analysis and Linear Discriminant Analysis), in combination with variable selection approaches (Forward Selection and Genetic Algorithms), were compared, evaluating their capabilities in the geographical discrimination of wine samples. Sixty-two samples were analysed by means of dynamic headspace gas chromatography mass spectrometry (HS-GC-MS) and the entire chromatographic profile was considered to build the dataset. Since variable selection techniques pose a risk of overfitting when a large number of variables is used, a method for coupling data dimension reduction and variable selection was proposed. This approach compresses windows of the original data by retaining only significant components of local Principal Component Analysis models. The subsequent variable selection is then performed on these locally derived score variables. The results confirmed that the classification models achieved on the reduced data were better than those obtained on the entire chromatographic profile, with the exception of Extended Canonical Variates Analysis, which gave acceptable models in both cases. Copyright © 2008 John Wiley & Sons, Ltd. [source] Above- versus below-ground competitive effects and responses of a guild of temperate tree speciesJOURNAL OF ECOLOGY, Issue 1 2009K. David Coates Summary 1The neutral theory debate has highlighted the scarcity of robust empirical estimates of the magnitude of competitive effects and responses within guilds of co-occurring tree species. Our analysis quantifies the relative magnitude of all possible pairwise competitive interactions within a guild of nine co-occurring tree species in temperate forests of northern, interior British Columbia, and explicitly partitions the competitive effects of neighbours into the effects of shading versus the residual effects of ,crowding', assumed to reflect below-ground competition. 2Models that treated neighbours as equivalent in their competitive effects were the most parsimonious for the five species with the smallest sample sizes. For the remaining species (samples sizes of > 150 individuals), the best models estimated separate competition coefficients for all nine species of neighbours. We take this as evidence that species do indeed differ in their competitive effects, but that there can be a minimum sample size required to discriminate between them. 3There was a strong size-dependency in potential growth. Six species showed an optimal growth at a size between 5 and 20 cm diameter. Potential growth declined moderately to strongly as diameter increased. Sensitivity to crowding varied as a function of tree size for five of the nine species; however, this response was not consistent by tree species. 4The magnitude of reduction in growth due to crowding was greater on average than the reduction in growth due to shading, except for the two least shade tolerant conifers. Sensitivity to shading among the conifer species was correlated with their shade tolerance. 5The per capita effects of crowding by different species of neighbours varied widely. A large number of the estimated pairwise per capita competition coefficients were very low. The relative magnitude of the strength of intra- versus interspecific competition also varied widely among the tree species. 6Synthesis. Model selection techniques effectively separated above- and below-ground competition in complex forests, and allowed us to assess differences among species in competitive effects and responses. While below-ground effects were strong, they were due to proximity of neighbours from a very specific (and small) subset of strong competitors within the guild. Response to crowding varied with tree size but the nature of the relationship varied widely among the species. [source] Yield and cooking qualities of somaclonal variants of cv. Russet Burbank selected for resistance to common scab disease of potatoANNALS OF APPLIED BIOLOGY, Issue 2 2010C.R. Wilson We previously obtained somaclonal variants of the important French fry processing cultivar Russet Burbank with significantly enhanced resistance to common scab disease. In this study we have shown the commercial merit of a proportion of these variants through comparison of relative yield and tuber quality with the parent cultivar Russet Burbank. Whilst we showed a weak negative correlation between tuber yield (as assessed by weight of tubers per plant) and relative disease resistance within selected variants, we identified several with equivalent yields to the parent cultivar. Furthermore, two disease-resistant variants (TC-RB8 and NZ-24B) consistently yielded more tuber mass than the parent. The majority of our Russet Burbank variants showed equivalent tuber quality characteristics (occurrence of defects, tuber specific gravity and dry matter content, and flesh colour) and cooking qualities (fry colour and presence of dark end defects) to the parent cultivar. Independent testing by a commercial French fry processor confirmed these quality characteristics. We present data demonstrating that highly common scab disease-resistant somaclonal variants of Russet Burbank have commercially acceptable tuber yield and quality characteristics, comparable to the industry standard and parent Russet Burbank cultivar. We also demonstrate the value of in vitro cell selection techniques for potato cultivar improvement. [source] AL03 ADVERSE EVENTS: OUR RESPONSIBILITY FOR REPORTING, REVIEWING AND RESPONDINGANZ JOURNAL OF SURGERY, Issue 2009J. Collins The sustained production of competent surgeons in sufficient numbers to meet the increasing needs of society commences with recruitment and selection of the most able medical graduates. As the process begins through self-selection, accurate information must be readily available to enable these graduates make an informed judgement on their career choice. Each surgical discipline aspires to use best practice selection in order to identify those who have the potential to acquire the necessary standard of technical and non technical skills and attributes required to practice as a surgeon. A selection system must rank applicants effectively and be reliable, valid, fair, defensible, cost effective and feasible. Best practice selection commences with an analysis of the relevant knowledge, skills, abilities and attitudes associated with successful performance in the particular target job. This information is used to construct a person specification in order to identify selection criteria at a level appropriate for entry to training. Selection methods are then chosen which will best elicit measurable applicant behaviour related to these selection criteria. A number of selection methods are used which include structured references, curriculum vitae and interviews. Other methods available although rarely used include tests of mental ability, aptitude tests and personality inventories. More recently selection or assessment centres (a selection method, not a place) involving a combination of selection techniques such as written exercises, interviews and work simulations have been shown to be highly effective. Eligibility criteria for application (long listing), shortlising for interview, scoring of items within each selection method and overall % weighting for each method are important variables in the selection process. [source] Attitudes Towards Personnel Selection Methods: A Partial Replication and Extension in a German SampleAPPLIED PSYCHOLOGY, Issue 4 2003Bernd Marcus Cette recherche qui fait appel à un échantillon de 213 étudiants allemands porte sur les attitudes envers un ensemble de méthodes utilisées dans la sélection professionnelle. Son but premier était d'apporter un nouvel éclairage sur les différences culturelles qui marquent les réactions des candidats devant les techniques de sélection en reconstituant partiellement une étude de Steiner & Gilliland (1996) qui recueillirent des évaluations de l'acceptation du processus pour dix procédures différentes auprès d'étudiants français et américains. Des divergences significatives sont apparues au niveau des moyennes, mais aucune structure sous-jacente ne put rendre compte de ces différences. En général, les sujets des trois nations ont note les plus favorablement les méthodes répandues (l'entretien et le C.V.), ainsi que les procédures en rapport évident avec le travail (les tests d'échantillon de travail), puis les tests papier-crayon, tandis que les contacts personnels et la graphologie étaient négativement appréciés. Autre objectif important: éprouver la validité des courtes descriptions des instruments de sélection généralement utilisées dans les études comparatives portant sur ce thème. On a évalué deux fois les attitudes envers quatre types de tests imprimés, une premiére fois après la présentation de la description et une seconde fois à l'issue de la passation du test. La convergence prétest-posttest, de basse à moyenne, met en évidence de sérieux problémes en ce qui concerne ces descriptions des tests papier-crayon. On aborde aussi les leçons à en tirer quant aux jugements sur les pratiques de sélection du point de vue des candidats et pour les recherches à venir. This research examined attitudes towards a variety of personnel selection methods in a German student sample (N= 213). Its first objective was to shed further light on cultural differences in applicant reactions to selection techniques by partially replicating a study by Steiner and Gilliland (1996), who obtained ratings of process favorability for ten different procedures from two groups of French and American students. Results indicated a number of significant mean discrepancies but no systematic pattern appeared to underlie these differences. In general, subjects in all three nations rated widespread methods (e.g. interview, résumés) or obviously job-related procedures (work sample tests) most favorably, followed by paper-and-pencil tests, whereas personal contacts and graphology appeared in the negative range. A second major objective was to examine the validity of the brief descriptions of selection instruments often used in comparative studies on this topic. Attitudes towards four different types of written tests were assessed twice for this purpose, once after presenting descriptive information, and a second time after actual test administration. Low to moderate pretest,posttest convergence pointed to serious problems with these descriptions for paper-and-pencil tests. Implications for current evaluations of selection practices from the applicants' perspective and for future research are discussed. [source] A Latent Model to Detect Multiple Clusters of Varying SizesBIOMETRICS, Issue 4 2009Minge Xie Summary This article develops a latent model and likelihood-based inference to detect temporal clustering of events. The model mimics typical processes generating the observed data. We apply model selection techniques to determine the number of clusters, and develop likelihood inference and a Monte Carlo expectation,maximization algorithm to estimate model parameters, detect clusters, and identify cluster locations. Our method differs from the classical scan statistic in that we can simultaneously detect multiple clusters of varying sizes. We illustrate the methodology with two real data applications and evaluate its efficiency through simulation studies. For the typical data-generating process, our methodology is more efficient than a competing procedure that relies on least squares. [source] Model Selection in Estimating EquationsBIOMETRICS, Issue 2 2001Wei Pan Summary. Model selection is a necessary step in many practical regression analyses. But for methods based on estimating equations, such as the quasi-likelihood and generalized estimating equation (GEE) approaches, there seem to be few well-studied model selection techniques. In this article, we propose a new model selection criterion that minimizes the expected predictive bias (EPB) of estimating equations. A bootstrap smoothed cross-validation (BCV) estimate of EPB is presented and its performance is assessed via simulation for overdispersed generalized linear models. For illustration, the method is applied to a real data set taken from a study of the development of ewe embryos. [source] | ||||||||||