Lecture Notes in Statistics Vol. 1: R. A. Fisher: An Appreciation. Edited by S. E. Fienberg and D. V. Hinkley. XI, 208 pages, 1980~ Vol. 2: Mathematical Statistics and Probability Theory. Proceedings 1978. Edited by W. Klonecki, A. KOlek, and J. Rosinski. XXIV, 373 pages, 1980. Vol. 3: B. D. Spencer , Benefit-Cost Analysis ofData Used to Allocat~ Funds. VIII, 296 pages, 1980. Vol. 4: E. A. van Doorn, Stochastic Monotonicity and Queueing Applications of Birth-Death Proces ses. VI, 118 pages, 1981. Vol. 5: T. Rolski, Stationary Random Processes Associated with Point Processes. VI, 139 pages, 1981. Vol. 6: S. S. Gupta and D.-Y. Huang, Multiple Statistical Decision Theory: Recent Developments. VIII, 104 pages, 1981. Vol. 7; M. Akahira and K. Takeuchi, Asymptotic Efficiency of Statistical Estimators. VIII, 242 pages, 1981. Vol. 8: The First Pannonian Symposium on Mathematical Statistics. Edited by P. Revesz, L. Schmet terer, and V. M. Zolotarev. VI, 308 pages, 1981. Vol. 9: B. J0rgensen, Statistical Properties of the Generalized Inverse Gaussian Distribution. VI, 188 pages, 1981. Vol. 10: A. A. Mcintosh, Fitting Linear Models: An Application on Conjugate Gradient Algorithms. VI, 200 pages, 1982. Vol. 11: D. F. Nicholls and B. G. Quinn, Random Coefficient Autoregressive Models: An Introduction. V, 154 pages, 1982. Vol. 12: M. Jacobsen, Statistical Analysis of Counting Processes. VII, 226 pages, 1982. Vol. 13: J. Pfanzagl (with the assistance of W. Wefelmeyer), Contributions to a General Asymptotic Statistical Theory. VII, 315 pages, 1982. Vol. 14: GUM 82: Proceedings of the International Conference on Generalised Linear Models. Edited by R. Gilchrist. V, 188 pages, 1982. Vol. 15: K. R. W. Brewer and M. Hanif, Sampling with Unequal Probabilities. IX, 164 pages, 1983. Vol. 16: Specifying Statistical Models: From Parametric to Non-Parametric, Using Bayesian or Non Bayesian Approaches. Edited by J. P. Florens, M. Mouchart, J. P. Raoult, L. Simar, and A. F. M. Smith. XI, 204 pages, 1983. Vol. 17: I. V. Basawa and D. J. Scott, Asymptotic Optimal Inference for Non-Ergodic Models. IX, 170 pages, 1983. Vol. 18: W. Britton, Conjugate Duality and the Exponential Fourier Spectrum. V, 226 pages, 1983. Vol. 19: L. Fernholz, von Mises Calculus For Statistical Functionals. VIII, 124 pages, 1983. Vol. 20: Mathematical Learning Models - Theory and Algorithms: Proceedings of a Conference. Edited by U. Herkenrath, D. Kalin, W. Vogel. XIV, 226 pages, 1983. Vol. 21: H. Tong, Threshold Models in Non-linear Time Series Analysis. X, 323 pages, 1983. Vol. 22: S. Johansen, Functional Relations, Random Coefficients and Nonlinear Regression with Application to Kinetic Data. VIII, 126 pages. 1984. Vol. 23: D. G. Saphire, Estimation of Victimization Prevalence Using Data from the National Crime Survey. V, 165 pages. 1984. Vol. 24: T. S. Rao, M. M. Gabr, An Introduction to Bispectral Analysis and Bilinear Time Series Models. VIII, 280 pages, 1984. Vol. 25: Time Series Analysis of Irregularly Observed Data. Proceedings, 1983. Edited by E. Parzen. VII, 363 pages, 1984. ctd. on IneIde beck_ Lecture Notes in Statistics Edited by D. Brillinger, S. Fienberg, J. Gani, J. Hartigan, and K. Krickeberg 35 Linear Statistical Inference Proceedings of the International Conference held at Poznan, Poland, June 4-8, 1984 Edited by T. Calinski and W. Klonecki S pri nger-Verlag Berlin Heidelberg New York Tokyo Editors T. Calinski W. Klonecki Mathematical Institute of the Polish Academy of Sciences ul. Kopemika 18, 51-617 Wroclaw, Poland AMS Subject Classification: 62-06, 62FXX, 62GXX, 62MXX ISBN-13: 978-0-387-96255-9 e-ISBN-13: 978-1-4615-7353-1 DOl: 10.1007/978-1-4615-7353-1 Library of Congress Cataloging-in-Publication Data. Main entry under title: Linear statistical inference. (Lecture notea in statistics; 35) 1. Linear models (Statistics)-Congreaaea.1. Calinski, T. II. KIonecki, W. (Wrtold) III. Series: Lecture notea in statistics (Springer-Verlag); 0A276.L54841985 519.5 85-25096 This work is subject to copyright. All rights are reaerved, whether the whole or part of the material is concerned, specifically those of translation, reprinting, re-use of illustrations, broadcasting, reproduction by photocopying machine or similar means, and storage in data banks. Under § 54 of the German Copyright Law where copies are made for other than private use, a fee is payable to ·Verwertungsgeaellschaft Wort", Munich. @ by Springer-Verlag Berlin Heidelberg 1985 III FOREWORD An International Statistical Conference on Linear Inference was held in Poznan, Poland, on June 4-8, 1984. The conference was organized under the auspices of the Polish Section of the Bernoulli Society, the Committee of Mathematical Sciences and the Mathematical Institute of the ,Polish Academy of Sciences. The purpose of the meeting was to bring together scientists from vari ous countries working in the diverse areas of statistical sciences but showing great interest in the advances of research on linear inference taken in its broad sense. Thus, the conference programme included ses sions on Gauss-Markov models, robustness, variance components~ experi mental design, multiple comparisons, multivariate models, computational aspects and on some special topics. 38 papers were read within the vari ous sessions and 5 were presented as posters. At the end of the confer ence a lively general discussion session was held. The conference gathered more than ninety participants from 16 countries, representing both parts of Europe, North America and Asia. Judging from opinions expressed by many participants, the conference was quite suc cessful, well contributing to the dissemination of knowledge and the stimulation of research in different areas linked with statistical li near inference. If the conference was really a success, it was due to all its participants who in various ways were devoting their time and efforts to make the conference fruitful and enjoyable. First who de serve thanks are all the speakers and authoFs, the chairmen of ses sions, and the discussants. They made a good job, highly appreciated by the majority of the conference attendants. A smooth run of the con ference is to be attributed to the efforts of the local organizing com mittee skillfully headed by Dr. R. Kala from the Department of Mathe matical and Statistical Methods of the Poznan Academy of Agriculture and Dr. R. Zmy~lony from the Wroclaw branch of the Mathematical Insti tute of the Polish Academy of Sciences. This volume contains about a half. out of the number of 43 papers pre sented at the conference, and represents its main features and results. We would like to express thanks to all authors who decided to undertake the task of preparing their papers for publishing in the proceedings. IV The standard of the papers owes very much to the work of a number of referees (a list of their names being included at the end of the vol ume) to whom not only the editors, we think, but also the authors are very greatful. We apologize, if some of the authors of submitted papers have possibly found the referee demandb too restrictive. In the final editorial work we were very much helped by many of our co-workers in Wroclaw and in Poznan, and also by the administrative staff of the Mathematical Institute of the Polish Academy of Sciences in Warsaw. It is impossible to mention the names of all of them, to whom we owe so much, but we would like to thank in particular Dr. S. Zontek. Also we would like to thank Ms. A. Go~dzik and Ms. T. Rejnie wicz for their excellent typing work. Last, but not least, let us ex press sincere thanks .to the Publisher for their efficient and friendly co-operation. T. Calinski w. Klonecki v CONTENTS 1. H. Caussinus SOME GEOMETRIC TOOLS FOR THE GAUSSIAN J. Vaillant LINEAR MODEL WITH APPLICATIONS TO THE ANALYSIS OF RESIDUALS . • 1 2. K. Christaf APPROXIMATE DESIGN THEORY FOR A SIMPLE F. Pukelsheim BLOCK DESIGN WITH RANDOM BLOCK EFFECTS 20 3. L.C.A. Carsten RECTANGULAR LATTICES REVISITED 29 4. C.~l. Dunnett MULTIPLE COMPARISONS BETWEEN SEVERAL TREATMENTS AND A SPECIFIED 39 TREAT~1ENT 5. H. Drygas MINIMAX-PREDICTION IN LINEAR MODELS 48 6. N. Gaffke SINGULAR INFORMATION MATRICES, DIREC TIONAL DERIVATIVES AND SUBGRADIENTS IN OPTIMAL DESIGN THEORY • 61 7. S. Gnat A NOTE ON ADMISSIBILITY OF IMPROVED J. Kleffe UNBIASED ESTIMATORS IN TWO VARIANCE COMPONENTS MODELS. 78 8. J. Jureckava LINEAR STATISTICAL INFERENCE BASED ON L-ESTIMATORS • • • 88 9. S. Kageyama CONNECTED DESIGNS WITH THE MINIMUM NUMBER OF EXPERH1ENTAL UNITS . • . 99 10. C.G. Khatri SOME REMARKS ON THE SPHERICAL DISTRI- BUTIONS AND LINEAR MODELS • • 118 11 • J. Kleffe ON COMPUTATION OF THE LOG-LIKELIHOOD FUNCTIONS UNDER MIXED LINEAR MODELS 135 12. J. Kleffe SOME REMARKS ON IMPROVING UNBIASED ESTIMATORS BY MULTIPLICATION WITH A CON STANT • • • • • • • • • • • • • •• 1 50 13. K. Klaczynski ON IMPROVING ESTIMATION IN A RESTRICTED P. Pardzik GAUSS-MARKOV MODEL • • • • • • • • •• 162 VI 14. M. Krzysko DISTRIBUTION OF THE DISCRIMINANT FUNCTION • • • • • • • • • . • • • 170 15. L.R. LaMotte ADMISSIBILITY, UNBIASEDNESS AND NON NEGATIVITY IN THE BALANCED, RANDOM, ONE-WAY ANOVA MODEL • • • . • 184 16. T. Mathew INFERENCE IN A GENERAL LINEAR MODEL WITH AN INCORRECT DISPERSION MATRIX 200 17. S. Mejza A SPLIT-PLOT DESIGN WITH WHOLEPLOT TREATMENTS IN AN INCOMPLETE BLOCK DESIGN •. 211 18. E. Neuwirth SENSITIVITY OF LINEAR MODELS WITH RESPECT TO THE COVARIANCE MATRIX • 223 19. K. Nordstrom ON A DECOMPOSTION OF THE SINGULAR GAUSS-MARKOV MODEL • 231 20. H. Nyquist RIDGE TYPE M-ESTIMATORS • . • • • . 246 21. E. Torgersen MAJORIZATION AND APPROXIMATE MAJO RIZATION FOR FAMILIES OF MEASURES, APPLICATIONS TO LOCAL COMPARISON OF EXPERIMENTS AND THE THEORY OF MAJO- RIZATION OF VECTORS IN Rn. • • • 259 22. S. Zontek CHARACTERIZATION OF LINEAR ADMIS SIBLE ESTIMATORS IN THE GAUSS-MAR- KOV MODEL UNDER NORMALITY. • • •• 311 SOME GEOMETRIC TOOLS FOR THE GAUSSIAN LINEAR MODEL WITH APPLICATIONS TO THE ANALYSIS OF RESIDUALS H.Caussinus and J.Vaillant Laboratoire de Statistique et Probabilites Universite Paul Sabatier Toulouse, France Summary. We consider the gaussian linear model (1)Y = XS+E where .5f(Y) = Nn (jJ, a2In)' a> 0, jJ E Q (a linear subspace of IRn). This model is invariant under the group of transformations Y -+ aY + i; (a> 0, i; E Q) and a maximal invariant is the vector T of normed residuals. Thus, if (1) is considered as a null hypothesis to be challenged, the restriction to invariant procedures leads to perform the analysis via T. The matrix approach is not very convenient to deal with T because the mapping Y -+ T is not linear. In fact, if model (1) is true, T is uniformly distributed on the unit sphere S of Ql. • Under some alternatives it is easy to compute the density of T with respect to the uniform probability on S, for example when .5f(Y) = Nn (v ,w), v ~ Q • The formulation which we advocate leads to straightforward results concerning the optimality of some procedures and enables us to give a clear account of the assumptions which are used. The problem of k outliers detection is more specially discussed, including the case where k is not fixed. 1. Introduction and notation Throughout this paper NE(v,W) denotes the normal (gaussian) distribu tion on the Euclidean space E with mean v and variance operator W. The scalar product on E is denoted by <.,.> and the corresponding KEY WORDS: Gauss-Markov model; coordinate-free approach; analysis of residuals; outliers; Bayes procedures; distributions on spheres. 2 narm by II ·11 ~ The dual space af E is identified to' E by means af the scalar praduct in the usual way, So' that W is a symmetric linear 2 aperatar from E intO' E. The distributian NE (O,er IE) (er> 0, IE is the identity aperatar fram E intO' E) is called spherical narm~l; it is preserved by any arthaganal transfarmatian and the prajectians anta arthaganal subspaces are independently spherical narmal an each af these spaces. The unit sphere af E is denated by SE' the unifarm prabability an SE is UE, the arthaganal prajectar anta a linear subspace Q is denated by lTQ and Q.l is the subspace af E arthaganal to' Q. When the cantext is clear subspaces as indices may be drapped ar replaced by simpler anes: far example Sn instead af S ,etc. •. • lRn The prabability law af a randam variable (generally vectar) is denated by • ~(.) In the classical linear madel, a sequence af real randam variables Y1'Y2' ••• 'Yn is given. These are cansidered as the coordinates of a n vector Y with respect to a canonical basis e = ( e1, ••• ,en I of lR . If the matrix of variances-covariances of the Yi'S is er2r (known up to' the factar er2 and nansingular) the metric on lRn is chosen such that the n x n matrix of the scalar products <ei ,ej >, i, j = 1, •.• ,n, -1 2 is r ,which implies that the variance operator of Y is er In. Now the gaussian linear model is I.i e: Q, (1) where Q is a given subspace of lRn, dim(Q) = q, 0< q< n. This model is invariant under the group of transformations Y+ aY+~ (a>O, ~e:Q) and a maximal invariant is the vector of normed residuals T = lilT .1 (Y)\\ IT .1 (Y) • Q Q In the analysis of residuals model (1) is considered as a null hypothesis to be challenged. The restriction to invariant procedures leads to performing the analysis through T. In the framework of model 3 (1) the normed residuals,i.e. the coordinates of T in the basis e, do not have an easily handled distribution. However the distribution of the vector T is extremely simple since it is nothing more than the uniform probability on the unit. sphere of d-: I£ (T) = U .1. Q Under various alternatives to model (1) it is tempting to express the distribution of T with respect to in a coordinate free approach. Ud- This is done in Section 2 for the case where I£ (Y) = Nn (v , W), v rt Q. Section 3 gives applications to residual analysis emphasizing the case of outlier detection. Other applications are indicated in Section 4. Also in this section we discuss briefly a kind of robustness arising from the fact that I£(T) could be U.l without I£(Y) being normal. Q Finally Section 5 is devoted to the slightly different problem of "modified residuals". This section has been included for historical interest, still stressing the usefulness of the geometrical framework. For earlier papers using the coordinate - free approach to Gauss-Markov estimation the reader could refer to Kruskal (1960) and Drygas (1970). However the geometrical tools developed herein are somewhat different and turn out to be also closely related to papers on spherical symmetry, e.g. King (1980). 2. Technical results This section gives some useful probabilistic results. Lemmas 1 and 2 are well known properties of the normal distribution: see e.g. Dempster (1969), Chapter 12. Lemma 3 can be found in Degerine (1979) or Watson (1983), Chapter 2 (2.2.6). Lemma 4 is an obvious general result which leads to a straightforward derivation of Proposition 1. Lemma 1: If Z is a random vector with values in the Euclidean space E, dim (E) = m, then (i) 1 2(Z) = NE(O,IE) tot (ii) are independent (iii) Remark: Z is spherically distributed if (i) and (ii) hold.