Computer simulation can be used to demonstrate why the unbiased sample variance uses degrees of freedom (n-1). This is first demonstrated for sampling from a normal random variable, and in additional simulations for some selected non-normal random variables, namely, chi-square and binomial.

The statistical concept of sampling is often given little direct attention, typically reduced to the mantra "take a random sample". This low resource and adaptable activity demonstrates sampling and explores issues that arise due to biased sampling.

This article addresses the problem of estimating the proportion Pi[subscript S] of the population belonging to a sensitive group using optional randomized response technique in stratified sampling based on Mangat model that has proportional and Neyman allocation and larger gain in efficiency. Numerically, it is found that the suggested model is…

Examines the undercount problem in the 1990 census, the ways in which the Census Bureau has dealt with it in the past, and the Bureau's plans to avoid future undercounts. It also discusses the statistical concept of dual systems estimation in census counting as a means of lessening an undercount. (GR)

Discusses sampling bias problems in the use of the greatest lower bound (g.l.b.) to reliability and offers explicit expressions for the second order derivatives. This yields closed form expression for the asymptotic bias of both the g.l.b. and its numerator. Illustrates the approach through a numeric example. (SLD)

Explores whether sampling is better than head count for census taking and if there is a genuine undercount distinct from "floating" populations. Discusses whether the census should accommodate the various interests who have addressed the question of the quality of enumeration, as well as the larger responsibilities of demographers for…

Discusses the pros and cons of sampling to improve the census versus the traditional methods of census taking, and the problems that changes in procedure can create. Also discusses chronic problems in census taking, regardless of procedural methods used, and observations on how to lessen their impact. (GR)

Describes a sampling strategy which involves linked pairs of persons used to obtain bereaved respondents for a study examining loss and coping responses following a recent natural disaster. The sampling procedure appeared not to produce an obvious bias and was very beneficial in meeting the research objectives. (Author/NRB)

This chapter provides an overview of sampling methods that are appropriate for conducting online surveys. The authors review some of the basic concepts relevant to online survey sampling, present some probability and nonprobability techniques for selecting a sample, and briefly discuss sample size determination and nonresponse bias. Although some…

The vocabulary of sampling is examined in order to provide a clear understanding of basic sampling concepts. The basic vocabulary of sampling (population, probability sampling, precision and bias, stratification), the fundamental grammar of sampling (random sample), sample size and response rate, and cluster, multiphase, snowball, and panel…

Intended to provide an overview of program evaluation as it applies to the evaluation of faculty development and clinical training programs in substance abuse for health and mental health professional schools, this guide enables program developers and other faculty to work as partners with evaluators in the development of evaluation designs that…