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Dive into the research topics where Jan Wretman is active.

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Featured researches published by Jan Wretman.


The Statistician | 1995

Model Assisted Survey Sampling.

Richard N. Penny; C.-E. Sarndel; Bengt Swensson; Jan Wretman

PART I: Principles of Estimation for Finite Populations and Important Sampling Designs: Survey Sampling in Theory and Practice. Basic Ideas in Estimation from Probability Samples. Unbiased Estimation for Element Sampling Designs. Unbiased Estimation for Cluster Sampling and Sampling in Two or More Stages. Introduction to More Complex Estimation Problems.- PART II: Estimation through Linear Modeling, Using Auxiliary Variables: The Regression Estimator. Regression Estimators for Element Sampling Designs. Regression Estimators for Cluster Sampling and Two-Stage Sampling.- PART III: Further Questions in Design and Analysis of Surveys: Two-Phase Sampling. Estimation for Domains. Variance Estimation. Searching for Optimal Sampling Designs. Further Statistical Techniques for Survey Data.- PART IV: A Broader View of Errors in Surveys: Nonsampling Errors and Extensions of Probability Sampling Theory. Nonresponse. Measurement Errors. Quality Declarations for Survey Data.- Appendix A - D.- References.


Canadian Journal of Statistics-revue Canadienne De Statistique | 1985

Regression analysis and ratio analysis for domains: A randomization-theory approach*

Eva Elvers; Carl Erik Särndal; Jan Wretman; Göran Örnberg

In most surveys, inference for domains poses a difficult problem because of data shortage. This paper presents a probability sampling theory approach to some common types of statistical analysis for domains of a surveyed population. Simple and multiple regression analysis, and analysis of ratios are considered. Two new methods are constructed and explored which can improve substantially over the common method based on sample-weighted sums of squares and products. These new methods use auxiliary variables whose importance depends on the extent to which they succeed in explaining certain patterns in the regression residuals. The theoretical conclusions are supported by empirical results from Monte Carlo experiments.


Archive | 2003

Model assisted survey sampling

Carl-Erik Särndal; Bengt Swensson; Jan Wretman


Biometrika | 1976

Some results on generalized difference estimation and generalized regression estimation for finite populations

Claes M. Cassel; Carl Erik Särndal; Jan Wretman


Biometrika | 1989

The weighted residual technique for estimating the variance of the general regression estimator of the finite population total

Carl-Erik Särndal; Bengt Swensson; Jan Wretman


Archive | 1992

Introduction to More Complex Estimation Problems

Carl-Erik Särndal; Bengt Swensson; Jan Wretman


Archive | 1992

Basic Ideas in Estimation from Probability Samples

Carl-Erik Särndal; Bengt Swensson; Jan Wretman


Archive | 1992

Nonsampling Errors and Extensions of Probability Sampling Theory

Carl-Erik Särndal; Bengt Swensson; Jan Wretman


The Mathematical Gazette | 1993

Model Assisted Survey Sampling

Pamela Morris; Carl-Erik Särndal; Bengt Swensson; Jan Wretman


Archive | 1992

Estimation for Domains

Carl-Erik Särndal; Bengt Swensson; Jan Wretman

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