Numerous methods exist to determine the optimal number of classes when using latent profile analysis (LPA), but none are consistently correct. Recently, the likelihood incremental percentage per parameter (LI3P) was proposed as a model effect-size measure. To evaluate the LI3P more thoroughly, we simulated 50,000 datasets, manipulating factors…

A Monte Carlo simulation study was conducted to examine the performance of [alpha], [lambda]2, [lambda][subscript 4], [lambda][subscript 2], [omega][subscript T], GLB[subscript MRFA], and GLB[subscript Algebraic] coefficients. Population reliability, distribution shape, sample size, test length, and number of response categories were varied…

Purpose: Multilingual children are disproportionately represented on speech pathology caseloads, in part due to the limited ability of traditional language assessments to accurately capture multilingual children's language abilities. This systematic review evaluates the evidence for identification of language disorder in multilingual children…

The normal-distribution-based likelihood ratio statistic T[subscript ml] = nF[subscript ml] is widely used for power analysis in structural Equation modeling (SEM). In such an analysis, power and sample size are computed by assuming that T[subscript ml] follows a central chi-square distribution under H[subscript 0] and a noncentral chi-square…

Social scientists are frequently interested in assessing the qualities of social settings such as classrooms, schools, neighborhoods, or day care centers. The most common procedure requires observers to rate social interactions within these settings on multiple items and then to combine the item responses to obtain a summary measure of setting…

We evaluated the statistical power of single-indicator latent growth curve models (LGCMs) to detect correlated change between two variables (covariance of slopes) as a function of sample size, number of longitudinal measurement occasions, and reliability (measurement error variance). Power approximations following the method of Satorra and Saris…

The use of meta-analysis in industrial and organizational psychology has become quite common. Unfortunately, the understanding and research necessary to ensure appropriate application of the technique have not been as widespread. As part of a larger study, a content analysis of meta-analyses from the industrial and organizational psychological…

Purpose: The purpose of this study was to determine whether standard pharmaco-economic preference methods can be used to assess perceived quality of life in stuttering. Method: Seventy-five nonstuttering adults completed a standardized face-to-face interview that included a rating scale, standard gamble, and time trade-off preference measures for…

The nine-volume Survey Kit is designed to help readers prepare and conduct surveys and become better users of survey results. All the books in the series contain instructional objectives, exercises and answers, examples of surveys in use, illustrations of survey questions, guidelines for action, checklists of "dos and don'ts," and…

Argues that perception studies and ranking are lacking in validity and reliability because of small sample size, simplistic statistical analyses, and the evaluation of quality by educators. It is asserted that quality control is more valid when evaluated by the customers of education, i.e., the students. (11 references) (EA)