New Developments in Statistical Computing: New Bias Evaluation Features of EXPLOR—A Program for Assessing Experimental Design Properties

Longitudinal investigations play an increasingly prominent role in biomedical research. Much of the literature on specifying and fitting linear models for serial measurements uses methods based on the standard multivariate linear model. This article proposes a more flexible approach that permits specification of the expected response as an arbitrary linear function of fixed and time-varying covariates so that mean-value functions can be derived from subject matter considerations rather than methodological constraints. Three families of models for the covariance function are discussed: multivariate, autoregressive, and random effects. Illustrations demonstrate the flexibility and utility of the proposed approach to longitudinal analysis.     

Accent on Teaching Materials: Notices and Reviews of Important Teaching Materials

This article examines the probabilities of outcomes from rolling dice with the dimension 1 × 1 × r for various values of r. Experiments were conducted by school students and university students. The results of the experiments are given and the probabilities examined using a generalized linear model. Notes are also made about the value of the experiment in teaching the groups of students.     

Statistical Computing Software Reviews

This section is similar in organization to a Book Review section in other journals; however, software of interest to statisticians is the subject of review here. Emphasis is on software for microcomputers. Programs that operate only in larger mainframe computers will seldom receive review. Normally, producers of programs make a copy of their product available to the Section Editor, who then selects one or more persons to test the product and prepare a review.

Producers of computer software who wish to have their product reviewed are invited to contact the Section Editor, Professor Kenneth Berk, Department of Mathematics, 313 Stevenson Hall, Illinois State University, Normal, IL 61761.

Findings and opinions expressed in every review are solely those of the author. They should not be construed as reflecting endorsement of the product, or opinions held, by the American Statistical Association, nor is any warranty implied about any product reviewed.

STAN, Version II.0. David M. Allen. Available from Statistical Consultants, Inc., 462 E. High Street, Lexington, KY 40508. $300. Reviewed by Peter A. Lachenbruch     

Merger as a Strategic Response to Government Contracting Pressures

This article describes the planning, decision-making, implementation, and evaluation phases of a recent, successful merger of five small social service agencies in Grand Rapids, Michigan. The merger was undertaken as a conscious strategy to enable the newly formed Arbor Circle Corporation to cope more effectively with environmental uncertainty, especially in regard to government contracting. The successes and the struggles encountered in the merger are instructive for other nonprofits that may be contemplating this kind of organizational restructuring as well as those interested in the impact of contracting on the government-nonprofit relationship.