Randomization procedures are performed in order to maximize the internal validity of treatment outcome studies. Objections have been made that this practice undermines the external validity of these studies because it ignores patients' treatment preferences, thereby precluding the self-selection of treatment that can occur in the community. This…

Research regarding the optimal fielding of online surveys is in its infancy and just beginning to offer clear suggestions for effective recruiting of participants as well as techniques for maximizing the response rate. In this article, the authors discuss the process of recruiting participants by e-mailing invitations to a list of recipients…

The article presents the feature sampling signal detection (FS-SDT) model, an extension of the multivariate signal detection (SDT) model. The FS-SDT model assumes that, because of attentional shifts, different subsets of features are sampled for different presentations of the same multidimensional stimulus. Contrary to the SDT model, the FS-SDT…

The National Education Association's Task Force on Testing has stated its opinion that standardized tests are overused. The task force suggests that the application of sampling techniques and a variety of alternatives to current testing practices would accomplish the same purposes. Representatives of the testing industry have indicated that the…

The sampling distribution is a common source of misuse and misunderstanding in the study of statistics. The sampling distribution, underlying distribution, and the Central Limit Theorem are all interconnected in defining and explaining the proper use of the sampling distribution of various statistics. The sampling distribution of a statistic is…

Although popular literature cites between 25,000 and 100,000 parental child snatchings a year, no empirical studies have been conducted to support this estimate. To determine an empirical estimate of the extent of parental child snatchings, telephone interviews were conducted by Louis Harris and Associates with a representative cross section of…

Described herein are formulas and computational procedures for estimating the mean and second through fourth central moments of universe scores through multiple matrix sampling. Additionally, procedures are given for approximating the standard error associated with each estimate. All procedures are applicable when items are scored either…

Examines the question of how large a sample must be in order to produce empirical Bayes estimates which are preferable to other commonly used estimates, such as proportion correct observed score. (Author/RC)

Author considered the proper use of the LSD-type drugs, variously called hallucinogenic, mind-altering, mind-revealing, or psychedelic, and sampled the views of responsible researchers on the use of these drugs for mental health and for the study of the human mind and development. (Author/RK)

This research represents an attempt to look closely at the actions which children are expexcted to perform in the early stages of reading and writing when taught by systematic methods, containing a phonic ingredient. (Author)

This paper presents the finding of an investigation for determining course achievement utilizing the statistical technique of path analysis. (Author)

Participants in the D-19 symposium on aquatic sampling and measurement for water pollution assessment were informed that determining the extent of waste water stream pollution is not a cut and dry procedure. Topics discussed include field sampling, representative sampling from storm sewers, suggested sampler features and application of improved…

A procedure for testing heterogeneity of variance is developed which generalizes readily to complex, multi-factor experimental designs. Monte Carlo studies indicate that the Z-variance test statistic presented here yields results equivalent to other familiar tests for heterogeneity of variance in simple one-way designs where comparisons are…

Designs for sequential sampling procedures that adapt to cumulative information are discussed. A familiar illustration is the play-the-winner rule in which there are two treatments; after a random start, the same treatment is continued as long as each successive subject registers a success. When a failure occurs, the other treatment is used until…