Randomized experiments are commonly used to evaluate if particular interventions improve student achievement. While these experiments can establish that a treatment actually "causes" changes, typically the participants are not randomly selected from a well-defined population and therefore the results do not readily generalize. Three…

Research in fields other than education has found that studies with small sample sizes tend to have larger effect sizes than those with large samples. This article examines the relationship between sample size and effect size in education. It analyzes data from 185 studies of elementary and secondary mathematics programs that met the standards of…

Explains the characteristics and importance of random assignment in experimental research on education. Considers factors supporting causal inferences, the nature of "assignment units," differences between random sampling and random assignment, the characteristics of randomization tests, forms of random assignment, and effects of experimental…

Describes the nature and consequences of liberally or improperly applying the traditional reading research methodology and provides an argument for tempering judgments about the relative contributions that experimental studies make to the professional literature in reading. (SKC)

This article feeds into debate about the feasibility and usefulness of educational experiments by discussing methodological issues arising out of a study which sought causal links between teaching and learning of one aspect of French as a foreign language. The study involved two small-scale experiments which tested a hypothesis regarding the…

THE MANY ACTIVITIES RESULTING FROM THE RECENT EMPHASIS UPON IMPROVING EDUCATION SHOULD CONCERN THE MAJOR PROBLEMS, RESEARCH TOPICS, AND PRIORITIES IDENTIFIED THROUGH A SUGGESTED SYSTEM OF VOCATIONAL EDUCATION BOOKKEEPING IN WHICH RESULTS ARE REVIEWED BY APPROPRIATE STAFF AND RESOURCE PERSONNEL FROM BUSINESS, INDUSTRY, COLLEGES, AND UNIVERSITIES.…

Advantages and disadvantages of nonexperimental paradigms in mathematics education are discussed. Suggestions are made for action toward establishing such designs as quality research. (MP)

With an emphasis on the problems of control of extraneous variables and threats to internal and external validity, the arrangement or design of experiments is discussed. The purpose of experimentation in an educational institution, and the principles governing true experimentation (randomization, replication, and control) are presented, as are…

Documenting treatment integrity is an important issue in research and practice in any discipline concerned with prevention and intervention. However, consensus concerning the dimensions of treatment integrity and how they should be measured has yet to emerge. Advances from three areas in which significant treatment integrity work has taken…

The ascendant view in the current debate about education science -- experimentism -- is a reassertion of the randomized experiment as the methodological gold standard. Advocates of this view have ignored, not answered, long-standing criticisms of the randomized experiment: its frequent impracticality, its lack of external validity, its confinement…

The purpose of this paper is to summarize and evaluate experiments which examined the effects of teacher questions on student achievement. The studies reviewed are of two types: (a) training experiments, in which the independent variable is teacher training; and (b) skills experiments, in which the frequency and manner of use of a teaching skill…

The technique originating from the study of ecological systems for the examination of dynamic educational systems over time is utilized. The technique is based on the theory of energy exchanges in interactions between variables. Using this technique, interactions among variables can be specified and simulated over time using an analog computer.…

Discusses the need for awareness of real and potential problems in educational evaluation approaches, kinds of problems there are with true experimental designs and with quasi-experimental designs, and the criteria applied by the Joint Dissemination Review Panel to its review of educational programs. (MF)

After a brief introduction indicating the value of the first Follow Through evaluation, this document offers ideas about how a new wave of Follow Through approaches should be evaluated. The discussion is based on the premise that the form of an evaluation must be derived from the questions for which answers are sought, the audience(s) to whom the…

Problems with conducting randomized field experiments in education are explored. Focus is on problems encountered while evaluating a group of dropout prevention projects. Project planners were asked to manipulate the subject eligibility criteria until they identified as eligible three to four times as many students as they could serve. They were…