摘要:

One concern in the early stages of study planning and design is the minimum sample size needed to provide statistically credible results. This minimum sample size is usually determined via the use of simple formulas or, equivalently, from tables. The more popular formulas, however, involve large-sample approximations and hence may underestimate required sample sizes. This article provides empirical evidence indicating that this underestimation phenomenon is extreme for certain sample size formulas based on confidence interval width. Common sample size formulas that consider statistical power are also discussed; these are shown to perform quite well, even for small sample size situations.

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475628

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Even though there are no valid tests of block effects in randomized complete block and Latin square experiments, it is noted that a commonly used measure of efficiency is monotonically related to theFratios used inappropriately for testing the effectiveness of blocking. Because of this relationship one can give beginning students a useful interpretation of otherwise inappropriateFstatistics without introducing concepts of relative efficiency.

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475629

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475630

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A real data set of considerable intrinsic interest and offering considerable scope for investigation with different techniques of exploratory data analysis is examined using principal components analysis and the biplot. The analysis has an intuitively satisfying interpretation and illustrates well applications of the techniques. Plausible interpretations for the first and second principal components are suggested. A number of interesting aspects of the biplots are noted.

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475631

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

A gamma distribution with arbitrary scale parameter θ and shape parameterr< 1 can be represented as a scale mixture of exponential distributions.

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475632

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

C. R. Rao (1973, problem 5.11) constructed an example where a minimum variance unbiased estimator exists for the parameter function (1 – α)2but no uniformly minimum variance unbiased estimator exists for α itself. The example was further discussed by Romano and Siegel (1986, example 9.6) who exhibited the family of unbiased estimators for α; the nonexistence of a uniformly minimum variance unbiased estimator comes from the fact that for a fixed value α0of α the unbiased estimator with smallest variance depends on α0and hence no unbiased estimator has uniformly smallest variance. In this note we show that a natural continuation of the example leads to an estimating equation for α that produces the maximum likelihood estimator. A second example, taken from Fisher (1958), exhibits a similar property. This example is both simpler and less artificial than the first, and we have found it very useful for teaching purposes. The general result is closely related to Fisher's motivation of maximum likelihood estimation and provides a good teaching illustration of Fisher's argument.

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475633

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Proceedings of The Second International Conference on Teaching Statistics Edited by Roger Davidson and Jim Swift. Sponsored by the International Statistical Institute and the University of Victoria. Available from Conference Services, University of Victoria, P.O. Box 1700, Victoria, British Columbia V8W 2Y2, Canada. $35 (Canadian), plus $3 (Canadian) for postage and handling. Reviewed by Elliot A. Tanis

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475634

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

摘要:

Graphical Aids for Stochastic Processes. Available from Wadsworth and Brooks/Cole Advanced Books and Software, 511 Forest Lodge Road, Pacific Grove, CA 93950–5098; (408) 373–0728. Complete version, $99.95; introductory version, $39.95. Site license available. Reviewed by Sallie Keller-McNulty

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475635

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475636

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor

ISSN:0003-1305    

DOI:10.1080/00031305.1989.10475637

出版商:Taylor & Francis Group    

年代:1989

数据来源: Taylor