Most scientific computing packages contain facilities for stepwise regression and often for 'all subsets' and other techniques for finding 'best-fitting' subsets of regression variables. The application of standard theory can be very misleading in such cases when the model has not been chosen a priori, but from the data. There is widespread awareness that considerable over-fitting occurs and that prediction equations obtained after extensive 'data dredging' often perform poorly when applied to new data.
This monograph relates almost entirely to least-squares methods of finding and fitting subsets of regression variables, though most of the concepts are presented in terms of the interpretation and statistical properties of orthogonal projections. An early chapter introduces these methods, which are still not widely known to users of least-squares methods.
Existing methods are described for testing whether any useful improvement can be obtained by using any of a set of predictors. Spjotvoll's method for comparing two arbitrary subsets of predictor variables is illustrated and described in detail.
When the selected model is the 'best-fitting' in some sense, conventional fitting methods give estimates of regression coefficients which are usually biased in the direction of being too large. The extent of this bias is demonstrated for simple cases. Various ad hoc methods for correcting the bias are discussed (ridge regression, James-Stein shrinkage, jack-knifing, etc.), together with the author's maximum likelihood technique. Areas in which further research is needed are also outlined.
Les informations fournies dans la section « Synopsis » peuvent faire référence à une autre édition de ce titre.
Most scientific computing packages contain facilities for stepwise regression and often for 'all subsets' and other techniques for finding 'best-fitting' subsets of regression variables. The application of standard theory can be very misleading in such cases when the model has not been chosen a priori, but from the data. There is widespread awareness that considerable over-fitting occurs and that prediction equations obtained after extensive 'data dredging' often perform poorly when applied to new data.
This monograph relates almost entirely to least-squares methods of finding and fitting subsets of regression variables, though most of the concepts are presented in terms of the interpretation and statistical properties of orthogonal projections. An early chapter introduces these methods, which are still not widely known to users of least-squares methods.
Existing methods are described for testing whether any useful improvement can be obtained by using any of a set of predictors. Spjotvoll's method for comparing two arbitrary subsets of predictor variables is illustrated and described in detail.
When the selected model is the 'best-fitting' in some sense, conventional fitting methods give estimates of regression coefficients which are usually biased in the direction of being too large. The extent of this bias is demonstrated for simple cases. Various ad hoc methods for correcting the bias are discussed (ridge regression, James-Stein shrinkage, jack-knifing, etc.), together with the author's maximum likelihood technique. Areas in which further research is needed are also outlined.
Les informations fournies dans la section « A propos du livre » peuvent faire référence à une autre édition de ce titre.
Vendeur : Attic Books (ABAC, ILAB), London, ON, Canada
Hardcover. Etat : Near fine. Monographs on Statistics and Applied Probability 40. x, 229 p. 22 cm. Tables and figures. Hardcover. Tiny tear in bottom of front board. N° de réf. du vendeur 116465
Quantité disponible : 1 disponible(s)
Vendeur : Phatpocket Limited, Waltham Abbey, HERTS, Royaume-Uni
Etat : Good. Your purchase helps support Sri Lankan Children's Charity 'The Rainbow Centre'. Ex-library, so some stamps and wear, but in good overall condition. Our donations to The Rainbow Centre have helped provide an education and a safe haven to hundreds of children who live in appalling conditions. N° de réf. du vendeur Z1-C-014-02611
Quantité disponible : 1 disponible(s)
Vendeur : Anybook.com, Lincoln, Royaume-Uni
Etat : Good. This is an ex-library book and may have the usual library/used-book markings inside.This book has hardback covers. In good all round condition. No dust jacket. Please note the Image in this listing is a stock photo and may not match the covers of the actual item,450grams, ISBN:9780412353802. N° de réf. du vendeur 4149302
Quantité disponible : 1 disponible(s)
Vendeur : Anybook.com, Lincoln, Royaume-Uni
Etat : Good. Volume 40. This is an ex-library book and may have the usual library/used-book markings inside.This book has hardback covers. In good all round condition. Please note the Image in this listing is a stock photo and may not match the covers of the actual item,450grams, ISBN:9780412353802. N° de réf. du vendeur 5558327
Quantité disponible : 1 disponible(s)
Vendeur : Books Puddle, New York, NY, Etats-Unis
Etat : New. pp. 240 1st Edition. N° de réf. du vendeur 262463725
Quantité disponible : 1 disponible(s)
Vendeur : Majestic Books, Hounslow, Royaume-Uni
Etat : New. pp. 240. N° de réf. du vendeur 5384242
Quantité disponible : 1 disponible(s)
Vendeur : Biblios, Frankfurt am main, HESSE, Allemagne
Etat : New. pp. 240. N° de réf. du vendeur 182463719
Quantité disponible : 1 disponible(s)
Vendeur : Mispah books, Redhill, SURRE, Royaume-Uni
Hardcover. Etat : Like New. LIKE NEW. SHIPS FROM MULTIPLE LOCATIONS. book. N° de réf. du vendeur ERICA77304123538066
Quantité disponible : 1 disponible(s)