Examines simultaneous equation models, using a large national sample of women in their mid twenties: it is found that the number of children a woman plans to bear has only a small effect on intentions to participate in the labor force, although a woman's plans to participate in the labor force has a substantial effect on the total number of…

Four techniques for assessing differences between least-squares estimators of regression coefficients from group and individual-level data are summarized. The utility and suitability of all four approaches are discussed when (1) data are grouped by a nominal characteristic; (2) there are multiple regressors; or (3) individual-level data cannot be…

Historical regression uses the assumption that without intervention, growth at post-test will proceed at the same rate as at pre-test. Several methods of historical regression are compared with an illustrative example. (JKS)

The influence of financial considerations on college enrollment rates is demonstrated in an economic theory model incorporating both investment and consumption reasons for attending, with relevance to the theory of occupational choice. (MF)

Flow-diagrams, algorithms, decision logic tables, and concept maps are presented in detail as methods for teaching practical procedures, problem solving, and basic concepts in microbial genetics. It is suggested that the flexible use of these methods should lead to an improved understanding of microbial genetics. (Author/MA)

The author calls for teachers to seek changes in the content of school mathematics curriculum which will reflect the growing diversity of mathematical application. Two examples of such application which can be described by simple mathematics and involving easy manipulation are given. (MN)

Path analysis was used to reevaluate the analysis of covariance quasiexperimental study of the effectiveness of the Head Start program. Contrary to the original analysis, the alternative approach yields small positive estimates of effect. (Author/CTM)

A simplex model is presented for the analysis of longitudinal academic growth variables in which only one measure is obtained at each time. When this model fits the observed data, then reliabilities and unattenuated correlations can be estimated except for the first and last periods. (Author)

Observer disagreement is important because it limits the reliabilities of observational measures. To avoid this limitation, observers should be trained, and criterion-related and intraobserver agreement measures should be used both before and during a study. Several agreement coefficients are examined for their applicability. (Author/BW)

A procedure is presented for the analysis of rating data with correlated intrajudge and uncorrelated interjudge measurement errors. Correlations between true scores on different rating dimensions, reliabilities for each judge on each dimension and correlations between intrajudge errors can be estimated given a minimum of three raters and two…

Summarizes the Ising model of ligand binding as it applies to cooperative binding to long chain molecules. Also presents some illustrations which help to visualize the connection between the interaction parameters and the shape of the binding isotherm. (Author/MR)

A precise method of determining absorption maxima where Gaussian functions occur is described. The method is based on a logarithmic transformation of the Gaussian equation and is suited for a mini-computer. (MR)

Generating functions for the columns in Pascal's triangle are constructed through algebraic and geometric interpretations. (JT)

Described are various common misconceptions about the nature of mathematics and suggests that courses or activities based on model building might help change these. Two examples are offered. (SD)

Mathematical modeling was utilized in the planning and decision-making process involved in reorganizing a teaching clinic to effect continuity of care. The model interrelated physicians, time, and space, facilitating value judgments and decisions. The reorganization was successful and the outcomes remarkably similar to model predictions.…