Discussion of informetric distributions shows that generalized Leimkuhler functions give proper fits to a large variety of Bradford curves, including those exhibiting a Groos droop or a rising tail. The Kolmogorov-Smirnov test is used to test goodness of fit, and least-square fits are compared with Egghe's method. (Contains 53 references.) (LRW)

Describes a goodness-of-fit statistic that considers the imprecision with which ability is estimated and involves constructing item fit tables based on each examinee's posterior distribution of ability, given the likelihood of the response pattern and an assumed marginal ability distribution. Also describes a Monte Carlo resampling procedure to…

Demonstrates that the statistics of exceedances generates Lotka's Law--a widely-observed distribution of authors of scholarly papers and patents. The Frequency of production (papers or patents per year) and Lifetime (career duration) are exponentially distributed random variables. Empirical, phenomenological, and mathematical development shows…

Presents ways of using different software for visualizing sampling distributions from a variety of background distributions. Random numbers are used to produce samples of given size and the mean of each is calculated. The mean and standard deviation of these means are calculated, a grouped frequency table is produced, and a histogram is generated.…

Discusses the use of the Excel computer program to develop and distribute simple models that provide a clear visual representation of a chosen probability distribution's properties to students. (ASK)

Provides an overview of standard and modified normal theory and asymptotically distribution-free covariance and correlation structure analysis techniques and details Monte Carlo simulation results on Type I and Type II error control. Demonstrates through the simulation that robustness and nonrobustness of structure analysis techniques vary as a…

A molecular approach for introducing entropy in undergraduate physical chemistry course and incorporating the features of Davies' treatment that meets the needs of the students but ignores the complexities of statistics and upgrades the qualitative, intuitive approach of Lambert for general chemistry to a semiquantitative treatment using Boltzmann…

A statistical test for the detection of answer copying on multiple-choice tests is presented. The test is based on the idea that the answers of examinees to test items may be the result of three possible processes: (1) knowing, (2) guessing, and (3) copying, but that examinees who do not have access to the answers of other examinees can arrive at…

While Americans obsess over childhood concerns about obesity and the Internet, vastly greater numbers of children around the world are dealing with more basic survival issues. To put the world of childhood in some perspective, the author reviews a bevy of demographic statistics about young children. In this article, the author has noted…

This research examines the effect of increased testing time by comparing the four performance indices of randomly equivalent examinee subpopulations on sections of similar content and difficulty administered at different times on three SAT administrations. A variety of analyses were used in this study and found no evidence that the current SAT…

While most existing online learning environments cater for needs identified during the 1990s, a new generation of digital students has emerged in the developed world. Digital students are young adults who have grown up with digital technologies integrated as an everyday feature of their lives. Digital students use technology differently, fluidly…

This exploratory study, a one group pretest-posttest design, investigated the development of elementary preservice teachers' understandings of distribution as expressed in the measures and representations used to compare data distributions. During a semester-long mathematics methods course, participants worked in small groups on two statistical…

Relationships between Bayesian ability estimates and the parameters of a normal population distribution are derived in the context of classical test theory. Analogies are provided for use as approximations in work with item response theory (IRT). The following issues are addressed: (1) the relationship between the distribution of the latent…

A Monte Carlo study was used to examine the Type I error rates of five multivariate tests for the single-factor repeated measures model. The performance of Hotelling's T-squared and four nonparametric tests, including a chi-square and an "F" test version of a rank-transform procedure, was investigated for different distributions, sample…

A person's obtained score on a test provides an estimate of the individual's "true" score on that test. The obtained score is considered to have two parts, the true component and the error component. Classical test theory assumes that obtained scores for an individual over multiple administrations of the same test will lie symmetrically…