The present study explores how the visualization of an actor network enables researchers to understand mediating processes better by investigating relationships and effects among elements and entities other than human-actor accounts. In particular, the study presents how visualization may facilitate an understanding of the dynamics and structures…

This study examines the relationship between sample size and item parameter estimation precision when utilizing the one-parameter model. Item parameter estimates are examined relative to "true" values by evaluating the decline in root mean squared deviation (RMSD) and the number of outliers as sample size increases. This occurs across…

Determining how learners use MOOCs effectively is critical to providing feedback to instructors, schools, and policy-makers on this highly scalable technology. However, drawing inferences about student learning outcomes in MOOCs has proven to be quite difficult due to large amounts of missing data (of various kinds) and to the diverse population…

Aggregation of data is, by definition, an obscuring of details for the sake of achieving a summary. It is, therefore, potentially harmful to accuracy. Attention should be given to the aggregation that scores undergo prior to statistical tests. Two familiar research designs where this is important are a) in two groups/one measure cases, and b) in…

This paper addresses a variation of the traditional validity question asked of qualitative researchers. Here the question is not "How do we know the qualitative researcher's question is valid?" but rather, "How does the qualitative researcher choose from among a multitude of apparently valid or at least plausible…

Research with older persons suffering from physical illness presents numerous challenges to gerontologists. Issues of conceptualization pertaining to the definition of illness, its location in the research paradigm, and the context in which illness occurs must be addressed prior to dealing with methodological problems. Access to physically ill…

Some of the frustrations inherent in trying to incorporate qualifications of statistical results into meta-analysis are reviewed, and some solutions are proposed to prevent the loss of information in meta-analytic reports. The validity of a meta-analysis depends on several factors, including the: thoroughness of the literature search; selection of…

The first step in aggregating qualitative data is to establish parameters for cross site analysis. Establishing parameters should include: (1) building a conceptual framework, (2) defining units of analysis, (3) developing core questions, and (4) establishing guidelines for handling unique features in each site. Two basic approaches to analyzing…

Discussed are limitations of studies focused on group data and some alternative conventions that might be used in reporting data so that it accurately represents individual subjects' patterns of language development. Evidence is presented from (1) a study of mothers' attempts to elicit verbal behavior from their normally developing or moderately…

This paper is devoted to an analysis of the "Standards for Evaluation of Educational Programs, Projects, and Materials" as they apply to qualitative data. The most difficult ethical problem arises from the conflict between the right to privacy of research subjects and the right to know of audiences. There are two technical points in the…

The value of variance is emphasized, and the element of design, frequently not adequately understood, is clarified to underscore the importance of variance to the researcher. Two analytic methods, analysis of variance (ANOVA) and multiple regression, are discussed in terms of how each uses/applies variance. Advantages and major difficulties with…

Because health behavior is often concerned with dynamic constructs, a longitudinal approach to measurement is needed. The Longitudinal Guttman Simplex (LGS) is a measurement model developed especially for dynamic constructs exhibiting cumulative, unitary development measured longitudinally. Data from the Television Smoking Prevention Project, a…

Educational assessment concerns inference about students' knowledge, skills, and accomplishments. Because data are never so comprehensive and unequivocal as to ensure certitude, test theory evolved in part to address questions of weight, coverage, and import of data. The resulting concepts and techniques can be viewed as applications of more…

There has recently been a tremendous increase in the quantity of research published in gerontology. While the increase in the quantity of research has been regarded positively by gerontologists, there has been little discussion or evaluation of the quality of the research. Two articles that appeared in 1975 were both very critical of…

The selection of appropriate data sources for institutional research is discussed. It is suggested that the provision of timely, accurate information for administrative decision-making depends on the researcher's ability to determine which data are relevant to the problem. This is of particular concern for institutional researchers because they…