This paper discusses the benefits of using generalizabilty theory in lieu of classical test theory. Generalizability theory subsumes and extends the precepts of classical test theory by estimating the magnitude of multiple sources of measurement error and their interactions simultaneously in a single analysis. Since classical test theory examines…

This paper explains how analysis of covariance (ANCOVA) and related statistical corrections work and discusses difficulties with the use of these corrections under certain circumstances. ANCOVA is essentially a regression of a covariate variable on the dependent variable from the entire sample ignoring group membership, at least, if ANCOVA…

The use of repeated measures research designs is explored. Repeated measures designs are often advantageous and can be implemented in a variety of research settings. One of the main advantages in repeated measures designs is the control of subject variability. Other advantages are the reduction of error variance and economy in subject recruitment.…

Aptitude-treatment interaction (ATI) studies have been used with some frequency, yet many researchers do not understand fully what interaction effects are. Because the means for interactions involve fewer persons per mean, power to detect interaction effects is typically smallest for the highest-order interaction in a given design. This phenomenon…

Dealing with missing data is frequently necessary in social sciences research. There are many statistical methods for dealing with missing data. This paper focuses on four of the more basic methods: (1) listwise deletion; (2) pairwise deletion; (3) total mean substitution; and (4) variable mean substitution. Each of the methods is discussed, and…

The correlation coefficient is an integral part of many other statistical techniques (analysis of variance, t-tests, etc.), since all analytic methods are actually correlational (G. V. Glass and K. D. Hopkins, 1984). The correlation coefficient is a statistical summary that represents the degree and direction of relationship between two variables.…

The following article provides a brief primer and overview of multilevel and hierarchical linear modeling. The school-effects model with random effects is illustrated with a heuristic dataset. Finally, recommendations are presented for researchers studying learning disabilities who would like to utilize this methodology.

The computer user has played an active part in uncovering changes brought on with microcomputer technology. Electronic mail (or "E-mail"), which enables users to send and receive messages through bulletin board services ("BBSs"), is often considered one innovation of the computer revolution. A BBS provides opportunities for…

The need for humanistically-oriented research may be viewed as the unfinished business of humanistic psychology. Additional research is needed to support some of the theoretical positions of humanistic psychology which have emerged from clinical practice, education, and management consultation rather than from laboratories and field studies. The…

Individuals often estimate the probability of future events by the ease with which they can recall or cognitively construct relevant instances. Previous research has not precisely identified the cognitive processes mediating this "availability heuristic." Two potential mediators (imagery of the event, perceived reasons or causes for the…

The emerging concept of program theory and its function in program evaluation practice is the central focus of this paper. It appears that the traditional decision/adoption model, when considered in conjunction with the institutionalized beliefs, values, and methodological procedures of the state Cooperative Extension Services, meets the criteria…

Provides a brief introduction to the basics of artificial intelligence and expert systems and explains terms in general use. (CLB)

Defines the engineering method by: (1) giving a preliminary definition and examples of its essential term (heuristics); (2) comparing the definition to a popular alternative; and (3) presenting a simple form of the definition. This definition states that the engineering method is the use of engineering heuristics. (JN)

Discusses factors that interfere with students' effective use of heuristic procedures for invention in composition. (HTH)

The algo-heuristic theory is concerned with identifying unobservable cognitive processes and their unconscious component cognitive operations, including learning how to describe them algorithmically and heuristically, and how to devise specific instructional tools (algorithmic and heuristic) to develop cognitive processes much faster. (BW)