Non‐linear structural equation models with correlated continuous and discrete data

Structural equation models (SEMs) have been widely applied to examine interrelationships among latent and observed variables in social and psychological research. Motivated by the fact that correlated discrete variables are frequently encountered in practical applications, a non‐linear SEM that accommodates covariates, and mixed continuous, ordered, and unordered categorical variables is proposed. Maximum likelihood methods for estimation and model comparison are discussed. One real‐life data set about cardiovascular disease is used to illustrate the methodologies.     

Robust ANCOVA using a smoother with bootstrap bagging

Many robust analogs of the classic analysis of covariance (ANCOVA) method have been proposed, some of which are based on some type of regression smoother. A method that first appeared in this journal, which is relatively simple and performs well in simulations, is based on a running interval smoother combined with comparing medians or 20% trimmed means. It makes no parametric assumption about the regression lines and does not assume that the regression lines are parallel. A possible way of improving the efficiency of the running interval smoother is to use bootstrap bagging and a minor goal here is to report some results supporting this approach. The major goal is to consider how ANCOVA might be performed when bootstrap bagging is used. Simple extensions of extant approaches that use some type of bootstrap method were found to be unsatisfactory. However, a basic percentile bootstrap method was found to perform well in simulations. And a reanalysis of data dealing with teachers' expectations about the cognitive ability of students illustrates that bootstrap bagging can make a practical difference.     

Law,professional practice,and university preparation: Where do we go from here?

In this time of legal decisions which call much professional practice into question, it is well to ask ourselves questions as to why we are the object of court concern and how our preparation is related to our difficulties. It is suggested that current psychological practice is basically Aristotelian in nature and that our specialty suffers as a consequence. Several suggestions are presented for adjustments in university preparation. Intelligence testing and ability grouping are referred to throughout, for they have been primary targets of the courts. Examples pertaining to personality and other often measured psychological variables could have as appropriately been offered.     

What procedural due process means to a school psychologist: A dialogue

Courts and the Congress have recently extended to school children safeguards encompassed by procedural due process in cases involving disciplinary suspensions and special education placements. The meaning of due process and its implications for psychologists are illustrated in a hypothetical dialogue between a constitutional lawyer and a school psychologist.