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Biomedical subjects

G H McClelland

Publications and source records attributed to G H McClelland.

9 recordsLinked to original sources
PubMed2001

Estimating and testing mediation and moderation in within-subject designs.

Analyses designed to detect mediation and moderation of treatment effects are increasingly prevalent in research in psychology. The mediation question concerns the processes that produce a treatment effect. The moderation question concerns factors that affect the magnitude of that effect. Although analytic procedures have been reasonably well worked out in the case in which the treatment varies between participants, no systematic procedures for examining mediation and moderation have been developed in the case in which the treatment varies within participants. The authors present an analytic approach to these issues using ordinary least squares estimation.

Data Interpretation, Statistical↗
PubMed1993

Statistical difficulties of detecting interactions and moderator effects.

Although interaction effects are frequently found in experimental studies, field researchers report considerable difficulty in finding theorized moderator effects. Previous discussions of this discrepancy have considered responsible factors including differences in measurement error and use of nonlinear scales. In this article we demonstrate that the differential efficiency of experimental and field tests of interactions is also attributable to the differential residual variances of such interactions once the component main effects have been partialed out. We derive an expression for this residual variance in terms of the joint distribution of the component variables and explore how properties of the distribution affect the efficiency of tests of moderator effects. We show that tests of interactions in field studies will often have less than 20% of the efficiency of optimal experimental tests, and we discuss implications for the design of field studies.

Bias↗
PubMed1991

Measuring contraceptive values: an alternative approach.

Previous assessments of individuals' values for various contraceptive consequences have employed one of four methodologies: free elicitation, direct ratings, multiple regression, or factor analysis. All four methodologies are flawed because they produce group rather than individual values, relying on rating scales, and fail to incorporate information regarding consequence trade-offs. Axiomatic conjoint measurement is proposed as an alternative methodology and used to determine individuals' values for a selected set of contraceptive consequences at two stages of the family-planning career.

Attitude↗
PubMed1991

Communicating the risk from radon.

A prominent television station developed a special series of newscasts and public service announcements about radon. This was combined with their advertising of the availability of reduced-price radon test kits in a local supermarket chain. The large number of test kits sold was a success from a marketing perspective, but not from a public health perspective--especially because of the very small share of high readings that were mitigated. In contrast, a study of housing sales showed a much higher testing rate and corresponding mitigation when risk communication accompanied the housing transaction, rather than being directed toward the general public. This paper examines the relative effectiveness of these alternative approaches to radon risk communication, emphasizing the implications for developing and implementing radon programs.

Communication↗
PubMed1987

Use of the maximal-operant principle to motivate children's intrinsic interest.

The present research examined the hypothesis that in contrast to theory and research indicating that tangible reward decreases subsequent interest in enjoyable academic activities, rewards are perceived by adults as effective techniques to maximize long- and short-term subsequent interest for academic tasks of both high and low initial interest level. The results of our first three studies demonstrated that college students and parents view tangible reward as more effective than other less controlling techniques to enhance intrinsic motivation and value rewards more for intrinsically interesting academic behaviors in comparison with others (e.g., prosocial behaviors). Our fourth study supported the hypothesis that adults do not subscribe to the minimal-sufficiency analysis of increasing intrinsic motivation but prefer a maximal-operant principle in which the likelihood of producing long-term interest in academic tasks is assumed to vary positively with the size of a reward. Our fifth and sixth studies investigated illusory correlation as one mechanism that may perpetuate beliefs about the assumed positive relation between tangible reward and intrinsic interest in academic tasks.

Achievement↗
PubMed1987

Evaluation of eight methods for estimating creatinine clearance in men.

Eight methods for estimating creatinine clearance (CLcr) were compared in 65 men with serum creatinine concentrations (SCr) less than or equal to 1.5 mg/dL (group 1) and 65 men with SCr greater than 1.5 mg/dL (group 2). All patients had SCr values that did not fluctuate by more than +/- 10% for two weeks before and two weeks after measurement of CLcr. For each patient, predictions of CLcr by each of eight currently used formulas were compared with measured CLcr values; both regression analysis and predictive error analysis were used. Group 1 patients ranged in age from 32 to 64 years (mean, 53), weighed from 48 to 105 kg (mean, 73), and were from 63 to 79 inches in height (mean, 69). Group 2 patients ranged from 26 to 63 years of age (mean, 53), weighed from 34 to 141 kg (mean, 80), and were from 63 to 76 inches in height (mean, 70). Measured CLcr values ranged from 29.8 to 197 mL/min in group 1 and from 2.8 to 118 mL/min in group 2. Ranges of SCr values were 0.7-1.5 mg/dL (mean, 1.1) in group 1 and 1.6-7.1 mg/dL (mean, 2.8) in group 2; the formula of Cockcroft and Gault, which uses age, body weight, and SCr, had the highest correlation and the greatest accuracy in group 1, whereas the formula of Jelliffe, which uses body surface area and SCr, had the highest correlation and the greatest accuracy in group 2. Estimation of creatinine clearance can be improved by identification and use of the formula that is best suited to a specific patient population.

Adult↗
PubMed1981

Determining the impact of sex preferences on fertility: a demonstration study.

The stopping rule measure of sex preferences represents a combination of psychological measures of preference and behavioral intentions. This study of 172 college students demonstrates that the stopping rule measure is a useful and practical method of measuring sex preferences. The results further indicate that parity progression ratio measures inherently underestimate the effect of sex preferences on individual fertility because they incorrectly assume that sex preferences (a) are homogeneous within the population and (b) can only act to increase, not to decrease, fertility. Use of the stopping rule measure to predict the possible effects of sex preselection techniques on fertility is also discussed.

Decision Making↗
PubMed1979

Determining the impact of sex preferences on fertility: a consideration of parity progression ratio, dominance, and stopping rule measures.

The two methods commonly used to assess the effect of sex preferences on fertility are inadequate to the task. Parity progression ratio analyses suffer from logical problems stemming from the heterogeneity of sex preferences and the riskiness of fertility decisions. While conjoint measurement-dominance procedures overcome these logical problems, they cannot yield quantitative estimates of the impact of sex preferences on fertility. A stopping rule measure which overcomes these limitations is proposed and described and its potential for determining the effect of sex predetermination methods on population is discussed.

Attitude↗