A probabilistic hypothesis testing procedure to assess the fit of hypothesized hierarchical structures for test item data is discussed. Statistical procedures are presented which are useful for evaluating the fit of data of a certain class of probabilistic models. These models apply to sets of dichotomous (O,1) responses for which there are…

The use of paper folding to demonstrate polygons which give plane tessellations, conic sections, and the solutions to several problems is described. (SD)

Simplicity and flexibility of the full rank linear model motivated this paper which introduces researchers to the theory necessary to understand the model and apply the theory in the analysis of some standard fixed effects experimental designs. The theory and examples should help researchers use the model as an experimental tool and a model for…

From a series of studies financed under a grant of the Rockefeller Foundation for work in the area of production functions and income distributions.

Aside from the theoretical issues involving the validity of inferences from surveys, the basic problem of producinq unbiased estimates of regression parameters and estimates of the associated standard errors has been a particularly difficult issue in dealing with results from stratified multistage sample designs such as the one used in the…

The problem of model estimation when the data are collinear was examined. Though the ridge regression (RR) outperforms ordinary least squares (OLS) regression in the presence of acute multicollinearity, it is not a problem free technique for reducing the variance of the estimates. It is a stochastic procedure when it should be nonstochastic and it…

It is noted that helping children learn how to solve problems has become a major goal for school mathematics. However, many children are not very successful at deciding what operation is appropriate for solving a given problem, and teachers often have difficulty describing or explaining how to identify the key features of a particular problem that…

For many reasons, students do not always perform on tests in ways that are congruent with their true abilities or achievement levels. Problems of this sort may be especially common on Title I evaluations where the tests administered are too difficult for a large percentage of the students. Such considerations raise the questions of whether…

Working from the premise that for any given periodical title there is some frequency of use at which it becomes cheaper for a library to acquire the publication than to borrow it, this report presents a mathematical model for estimating the costs of options associated with acquiring periodicals. Cost elements included in the model are initial…

Guttman's facet theory is described as a method for quantifying information concerning attitudes. It is stated that attitude items are not negatively correlated for usual populations. An attitude is defined as a delimited totality of behavior with respect to something and its components are elements of a set. The first step in facet research…

A project was developed to link together the computer and an operations research technique (goal programming) and to bring them to bear on problems in improving vocational education planning. The process involves using the computer to solve a mathematical model designed to determine trade-off values among alternative goals and plans. Simulating…

Three procedures used to control Type I error rate in stepwise regression analysis are forward selection, backward elimination, and true stepwise. In the forward selection method, a model of the dependent variable is formed by choosing the single best predictor; then the second predictor which makes the strongest contribution to the prediction of…

The purpose of this study was to review existing human operator modeling techniques and evaluate their potential utility for performance measurement applications (e.g., to support the type of flight simulation research that entails accounting for the perception and utilization of various cues). The major human operator characteristics that ought…

The major advantage of sequential classification, a technique for automatically classifying documents into previously selected categories, is that the entire document need not be processed before it is classified. This method assumes the availability of a priori categories, a selection of keywords representative of these categories, and the a…

The inputs to mathematical models of library operations require periodic updating. The data collection effort necessary for such updating can be quite expensive; however, if the data collected can serve multiple purposes, the costs can perhaps be justified. A management information system (MIS) offers a vehicle for multiple uses of data, and thus…