PREDICTING MARITAL SUCCESS AFTER FIVE YEARS: ASSESSING THE PREDICTIVE VALIDITY OF FOCCUS

Engaged couples who took a premarital inventory called FOCCUS were contacted 5 years later to see if their scores would predict their future marital success. Results showed that FOCCUS successfully predicted the future marital success of most couples, supporting the predictive validity of FOCCUS. The results also indicate that FOCCUS and PREPARE are roughly comparable in terms of their predictive validity.     

An intelligent system for experimental design-some ideas

There is a growing movement towards the construction of statistical expert systems by statisticians to assist incertain aspects of their work. As one of the most'abused’ areas, experimental design could benefit from a system ofthis type. This paperoutlines some ideas on how a system for intelligently constructing designs could be built.     

Setting Up a Rural Private Practice*

This irreverent, somewhat breezy paper describes the experience of the author in establishing a private practice in an unusual setting and offers some observations for others. Editor.     

Maximum Value of Hotelling's T 2 Statistics Based on the Successive Differences Covariance Matrix Estimator

In statistical process control applications, the multivariate T ² control chart based on Hotelling's T ² statistic is useful for detecting the presence of special causes of variation. In particular, use of the T ² statistic based on the successive differences covariance matrix estimator has been shown to be very effective in detecting the presence of a sustained step or ramp shift in the mean vector. However, the exact distribution of this statistic is unknown. In this article, we derive the maximum value of the T ² statistic based on the successive differences covariance matrix estimator. This distributional property is crucial for calculating an approximate upper control limit of a T ² control chart based on successive differences, as described in Williams et al. (2006 Williams , J. D. , Woodall , W. H. , Birch , J. B. , Sullivan , J. H. ( 2006 ). On the distribution of T ² statistics based on successive differences . J. Qual. Technol. 38 : 217 – 229 .[Taylor & Francis Online], [Web of Science ®] , [Google Scholar]).