A relationship between experimental and statistical controls is considered in an effort to show how this relationship affects the power of an experiment. Statistical rather than experimental controls are often used to reduce the effect of subjects at the extremes of individual difference. This results in attrition of actual experimental subjects.…

Marine education research designs are discussed, and student learning outcomes while monitoring a coral reef is evaluated. Changes in environmental knowledge and attitudes, ecological intention to act, and direct reef experience were investigated. Differences between student pre-test and the post-test responses were observed, and analysis is…

A Monte Carlo study was done to determine the adequate sample size for quasi-experimental regression studies, which compare regression lines for two groups and estimate their point of intersection. Populations of 1,000 subjects in each of two groups were constructed (using random normal deviates) to yield equivalent regression lines of opposite…

An approach for merging quantitative-qualitative data in order to enlarge the evaluators' perspective and provide an enriched data base for evaluating elusive evaluation problems in school settings is described. Mini-case studies were conducted over a period of three years in 11 urban schools to examine the impact of an arts-in-the-schools program…

Counseling psychology is a relatively new field that is gaining autonomy and respect. Unfortunately, research efforts in the field may lack an appropriate research design. This paper considers some of the more common types of research design and the associated threats to their validity. An example of each design type is drawn from the counseling…

Community-based educational programs for older adults are difficult to evaluate due to randomization and control factors. In order to investigate, under a quasi-experimental research design, the contribution of an educational program on retirement issues to participants' quality of life, and to study the program enrollment patterns, 21 people…

Perhaps no facet of long-term care (LTC) research has received as much attention as the evaluation of community-based LTC demonstrations. Recent thinking has called into question the validity and policy relevance of the findings of these studies, yet their efforts will continue to receive strong financial backing. The time has come for LTC…

A classroom/laboratory exercise has been used to introduce college students to factorial research designs, differentiate between interpretations for experimental and quasi-experimental variables, and exemplify application of laboratory research methods to test practical questions (advertising claims). The exercise involves having randomly divided…

Differential achievement growth patterns between comparison groups is a problem associated with data analysis in compensatory education programs. Children in greatest need of additional assistance, are usually assigned to the program rather than to an alternative treatment so that the comparison groups may vary in several ways, in addition to the…

The purpose of this study was to compare the results of an analysis of covariance design to a method developed by the authors called within-class regression. Application of this statistical method can be to any quasiexperimental design with a large number of groups. A test of statistical significance to use with the within-class regression…

A sample of 51 fourth graders' perceptions of the quality of their school life, including satisfaction with school, commitment to their classwork, and attitudes toward teachers was assessed at the beginning and end of the school year, as were beliefs concerning responsibility for successful, unsuccessful, and overall academic achievements. Results…

The central purpose of the present study was to evaluate several statistical techniques (analysis of variance (ANOVA) on raw gains, standardized ANOVA, standard analysis of covariance (ANCOVA), and z-score ANOVA) under various quasi-experimental conditions (three levels of reliability, three levels of sample size, three levels of gain, and the…

In recent years, the debate about the utilization of research studies that have been used to inform educational practice has been steadily growing. This debate is primarily the result of frustration; despite the investment of billions of dollars, learner outcomes have not significantly improved. One possible explanation is that most education…

This study explored the possibility of developing classroom strategies that would encourage physics teachers to put greater focus on a more qualitative, metacognitive approach to problem solving. The empirical part of this research was carried out with students approximately 16 years of age in physics (i.e., introductory Newtorian mechanics)…

The presence of artifactual bias in analysis of covariance (ANCOVA) and in matching nonequivalent control group (NECG) designs was empirically investigated. The data set was obtained from a study of the effects of a television program on children from three day care centers in Mexico in which the subjects had been randomly selected within centers.…