The models and procedures discussed in this paper are related to those presented in Bock and Aitkin (1981), where they considered the 2-parameter probit model and approximated a normally distributed prior distribution of abilities by a finite and discrete distribution. One purpose of this paper is to clarify the nature of the general EM (GEM)…

The effectiveness of Stout's procedure for assessing latent trait unidimensionality was studied. Strong empirical evidence of the utility of the statistical test in a variety of settings is provided. The procedure was modified to correct for increased bias, and a new algorithm to determine the size of assessment sub-tests was used. The following…

This paper details the pathway of development of early intervention program evaluation research along with the often-enumerated problems with research results. Early intervention evaluation, which was initiated in 1969, involves those organized efforts designed to remediate and/or reconcile developmental disabilities in young children up to the…

The Pearson and likelihood ratio statistics are frequently used for assessing the absolute fit of probability models. Researchers are often interested in comparing fits provided by different models which may have a subsuming or non-subsuming relation. A subsuming relation exists when the parameters of the reduced model form a subset of those…

This proposal attempts to follow in Allan Birnbaum's tradition by using Bayesian ideas to show that his mental test model possesses even broader applicability than previously realized. Birnbaum's two significant contributions to the theories of statistics and educational testing are: (1) the proof that the sufficiency and conditionality principles…

In the educational research literature alpha, the a priori level of significance, and p, the a posteriori probability of obtaining a test statistic of at least a certain value when the null hypothesis is true, are often confused. Explanations for this confusion are offered. Paradoxically, alpha retains a prominent place in textbook discussions of…

This article is a critical review of a number of statistical works, over the past 50 years, dedicated to the determination of the relative frequency of phonemes. (Author/RM)

In this study, the training effects of static and dynamic exercise programs on the firing patterns of 450 single motor units (SMU) in the human tibialis anterior muscle were investigated. In a six week program, the static group (N=5) participated in daily high intensity, short duration, isometric exercises while the dynamic group (N=5)…

This study compared the responses of 100 randomly selected students from a rural and an urban Missouri community-junior college campus. A stressful situation was defined as any one that causes the student to be concerned, anxious, or uncomfortable. Respondents were to indicate for each of 25 items whether certain situations caused them great,…

A new alternative to awarding "F" grades for course failure was investigated by the psychology department of Los Angeles City College, and initial results are reported in this study. Basically, a "W" grade was given to failing Psychology 1 students in place of "F" during the fall 1969 semester. The "W" could…

This paper discusses Bayesian m-group regression where the groups are arranged in a two-way layout into m rows and n columns, there still being a regression of y on the x's within each group. The mathematical model is then provided as applied to the case where the rows correspond to high schools and the columns to colleges: the predictor variables…

The study was initiated to learn more about incorporated farms in Wisconsin. Specific objective included: listing all corporations in the state with agriculture incomes, acquiring basic structural data in these units, analyzing differences between various types of corporation farms when classified according to nature of ownership, and determining…

This study is an analysis of the robustness of the Box-Tiao integrated moving averages model for analysis of time series quasi experiments. One of the assumptions underlying the Box-Tiao model is that all N values of alpha subscript t come from the same population which has a variance sigma squared. The robustness was studied only in terms of…

Stochastic approximation algorithms for least square error approximation to density and distribution functions are considered. The main results are necessary and sufficient parameter conditions for the convergence of the approximation processes and a generalization to some time-dependent density and distribution functions. (Author)

The harmonic mean and Kramer (1956) unequal n forms of the Tukey multiple comparison statistic were investigated for Monte Carlo Type I and Type II errors under conditions of assumption violations. The two major questions concerning the sensitivity of multiple comparison statistics for different types of pairwise contrasts and the affect of…