sample size

A Dictionary of Statistics;      8 words ...sample size The number of observations in a sample .

Effects of sample size (replicate number) on similarity measures in river...

Water Environment Research;  January 1, 1997 ;     700+ words ...ABSTRACT: The effects of sample size (the number of replicates) on 11 similarity measures...resampling. Most of these indices were strongly affected by sample size. However, as sample size increased, species composition and relative abundance...

Sample size and power analysis in medical research

Indian Journal of Dermatology, Venereology and Leprology;  March 1, 2004 ;     700+ words ......subjects should be included in their study (sample size) and how these subjects should be selected...If a study does not have an optimum sample size, the significance of the results in...of differences because of inadequate sample size.[1] Whatever outstanding results the...

Some Practical Guidelines for Effective Sample Size Determination.

The American Statistician;  August 1, 2001 ;     700+ words ...Sample size determination is often an important step in planning...some suggestions for successful and meaningful sample size determination. Also discussed is the possibility that sample size may not be the main issue, that the real goal is...

The saw-toothed behavior of power versus sample size and software...

The American Statistician;  May 1, 2003 ;     700+ words ......saw-toothed behavior of power versus sample size and software solutions: single binomial...exact binomial test is not monotone in sample size, subject to a constraint on Type I error...that there is no unique solution to the sample size problem, and they briefly mentioned...

Estimating Sample Size for Magnitude-Based Inferences.

Sportscience;  January 1, 2006 ;     700+ words ...Sample-size estimation based on the traditional method...using two new methods for estimating sample size for such studies, based on acceptable...spreadsheet includes a section for estimating sample size by the traditional method, which requires...

Optimal sample size for multiple testing: the case of gene expression...

Journal of the American Statistical Association;  December 1, 2004 ;     700+ words ......INTRODUCTION We consider the problem of sample size selection for experiments involving...multiple comparisons. Approaching the sample size question as a decision problem, we argue...solution needs to address the choice of sample size as part of a larger decision problem...

Relationship between Bayesian and frequentist sample size determination.

The American Statistician;  February 1, 2005 ;     700+ words ...1. INTRODUCTION 1.1 Overview Sample size determination is among the most commonly...For example, one chooses the smallest sample size sufficient to achieve specified power...parallels between Bayesian and frequentist sample size calculations. We seek functional relationships...

Sample size reestimation for clinical trials with censored survival data.

Journal of the American Statistical Association;  June 1, 2003 ;     700+ words ......presented methods for the estimation of sample size or power under a usual fixed sample...compliance, it is desirable to adjust the sample size and/or the duration of the trial for...initial assumptions and adjusting the sample size if necessary, to ensure adequate power...

Sample size and statistical power of randomised, controlled trials in...

Journal of Bone and Joint Surgery;  November 1, 2001 ;     599 words ......Bernstein,' entitled `Sample size and statistical power of randomised, controlled trials in orthopaedics' in the...Back S, Bernstein J. Sample size and statistical power of randomised controlled trials in orthopaedic surgery...

A decision tree for controlled trials.(Reprint)

Sportscience;  January 1, 2005 ;     700+ words ......Series vs Other Controlled Trials Posts-Only vs...References Appendix 1: Sample Size for Posts-Only...Trial Appendix 2: Sample Size for Fully Controlled...avoid bias in controlled trials). In a first...all types of controlled trials, but the ...

Sample size: more than calculations.(Statistical Practice)

The American Statistician;  August 1, 2003 ;     700+ words ......this need, there are multiple books on sample size calculations (Cohen 1988; Desu and Raghavarao...certain specific requirements for the right sample size (Bacchetti 2002). This approach to sample size calculations follows the pattern: (a...

Misconceptions about sample size, statistical significance, and treatment...

The Journal of Psychology;  November 1, 1997 ;     700+ words ......requires knowledge of the relationship between sample size and treatment effect. Because sample size (n) is in the denominator of the formula...relationship between treatment effect and sample size is often misunderstood (Bandt & Boen...

The saw-toothed behavior of power versus sample size and software size and...

The American Statistician;  May 1, 2002 ;     700+ words ......of trials. Software packages for sample size determination are readily available...the largest result from the three sample size calculations. For each of the endpoints, we determine a sample size for a one-sided 0.05 significance...

Power, effect and sample size using GPower: practical issues for...

Royal College of Midwives-Evidence-Based Midwifery;  December 15, 2007 ;     700+ words ...Abstract Background. The issue of sample size has become a dominant concern for UK...committees since their reform in 2004. Sample size estimation is now a major, but often...explore and address issues relating to sample size, effect size and power. Method. Basic...