When conducting experiments involving the measurement of physically related quantities, choosing an appropriate spacing for the experimental independent variable is a crucial procedure whose consequences may go beyond data graphical visualization. This is particularly true if the measured quantities are nonlinearly related and experimental errors…

This article gives a simple method for determining the maximum interval of existence for a solution of a single, autonomous, first-order differential equation as well as the behavior of the solution as the independent variable approaches the ends of the interval. The methods used are elementary enough to be included in an introductory differential…

Very little explanatory power is required in order for regressions to exhibit statistical significance. This article discusses some of the causes and implications. (Contains 2 tables.)

In behavioral research, interest is often in examining the degree to which the effect of an independent variable X on an outcome Y is mediated by an intermediary or mediator variable M. This article illustrates how generalized estimating equations (GEE) modeling can be used to estimate the indirect or mediated effect, defined as the amount by…

This paper discusses how a seldom-used statistical procedure, recursive regression (RR), can numerically and graphically illustrate data-driven nonlinear relationships and interaction of variables. This routine falls into the family of exploratory techniques, yet a few interesting features make it a valuable compliment to factor analysis and…

The logarithmic transformation is a commonly applied procedure in regression analysis when two or more variables have a nonlinear relationship. When the response variable is logarithmically transformed, confidence intervals for conditional means and predictions may actually be wider than their counterparts obtained from the model with the original…

A focus of grazing management courses is the cause-effect relationships between grazing livestock distribution and environmental and management variables. A learning module for the classroom was developed to enable students to actively study livestock distribution by analyzing recently collected data from an on-ranch situation. Data were collected…