Lecoutre, Lecoutre, and Poitevineau (2010) have provided sophisticated grounding for "p[subscript rep]." Computing it precisely appears, fortunately, no more difficult than doing so approximately. Their analysis will help move predictive inference into the mainstream. Iverson, Wagenmakers, and Lee (2010) have also validated…

In their seminal paper, Edwards and Parry (1993) presented the polynomial regression as a better alternative to applying difference score in the study of congruence. Although this method is increasingly applied in congruence research, its complexity relative to other methods for assessing congruence (e.g., difference score methods) was one of the…

P. R. Killeen's (2005a) probability of replication ("p[subscript rep]") of an experimental result is the fiducial Bayesian predictive probability of finding a same-sign effect in a replication of an experiment. "p[subscript rep]" is now routinely reported in "Psychological Science" and has also begun to appear in…

The sense that replicability is an important aspect of empirical science led Killeen (2005a) to define "p[subscript rep]," the probability that a replication will result in an outcome in the same direction as that found in a current experiment. Since then, several authors have praised and criticized 'p[subscript rep]," culminating…

This comment offers three descriptions of "p[subscript rep]" that start with a frequentist account of confidence intervals, draw on R. A. Fisher's fiducial argument, and do not make Bayesian assumptions. Links are described among "p[subscript rep]," "p" values, and the probability a confidence interval will capture…

When survey data are statistically analyzed, many times some of the data is missing. If the missing values are not correctly handled, results of the analysis may be dubious and publication may jeopardize the credibility of the organization preparing the report. This study examined four of the more commonly used methods of handling missing data.…

A strategy is proposed for conceptualizing moderating relationships based on their type (strictly correlational and classically correlational) and form, whether continuous, noncontinuous, logistic, or quantum. Results of computer simulations comparing three statistical approaches for assessing moderator variables are presented, and advantages of…

Characterized the methodology of case studies, using examples from science education, with regard to their potential for the analysis of innovation and formulation of emerging trends. The theoretical and empirical support of evaluation will generate a call for negotiation as the formula that regulates the assessment of a program's efficiency and…

The literature on validity provides much more guidance on how to collect various kinds of validity evidence than it does on which kinds of evidence to collect in specific cases. An argument-based approach to validation redresses the balance by linking the kinds of evidence needed to validate a test-score interpretation to the details of the…

The National Center for Education Statistics supported this conference as a first step in a dialogue among forecasters to benefit all in the field. Fifty forecasters representing 20 different federal agencies attended the day-long session. Objectives of the conference include: (1) to bring forecasters together for a forum to share information on…

Since problems associated with the statistical methodology of educational research are becoming increasingly important, this paper examines a subset of problems associated with the analysis and interpretation of aggregated data. Two major questions arise: (1) if a researcher knows the level (e.g., individual, teacher/classroom, school, school…

Since university enrollment forecasting is very important, many different methods and models have been proposed by researchers. Two new methods for enrollment forecasting are introduced: (1) the fuzzy time series model; and (2) the artificial neural networks model. Fuzzy time series has been proposed to deal with forecasting problems within a…

Marascuilo and Levin's (1970) notion of Type IV errors is extended, with respect to the interpretation of interactions in analysis of variance (ANOVA) designs. To help clarity what an interaction is and what it is not, in terms of the ANOVA model, the following points are made: (i) interactions should be thought of as linear contrasts involving…

The agreement between visual analysis and the results of the split-middle method of trend estimation was examined using a set of 24 stimulus graphs and 30 raters. Results revealed poor agreement between the two methods, and low sensitivity, specificity, and predictive ability for visual analysis in relation to statistical inferences. (JDD)

THE TOPICS OF EIGHT CONFERENCE PAPERS INCLUDE (1) THE PROBLEM OF DIFFERENTIATING EFFECTS OF SPECIFIC INSTRUCTION FROM EFFECTS OF OTHER INFLUENCES (GROWTH, ENVIRONMENT, AND SELF-INSTRUCTION), (2) CRITERIA FOR MEASURING CHANGE IN PROFICIENCY, AND (3) WAYS OF RELATING SUCH CHANGE TO OUTSIDE VARIABLES SUCH AS MEASURABLE CHARACTERISTICS OF LEARNERS AND…