Attributions of Responsibility for Obesity: Narrative Communication Reduces Reactive Counterarguing Among Liberals

Informed by theory and research on attributions and narrative persuasion, we compared the effectiveness of narrative and nonnarrative messages in changing attributions of responsibility for causes and solutions related to obesity in the United States. We randomly assigned 500 adults to view one of three messages (narrative, evidence, and a hybrid of the two) emphasizing environmental causes of obesity, or a no‐exposure control condition. The narrative condition increased the belief that societal actors (government, employers) are responsible for addressing obesity, but only among liberals. This pattern of results was partially explained by the success of the narrative condition in reducing reactive counterarguing, relative to the evidence condition, among liberals. We conclude with theoretical and practical implications.     

Functional measurement approach to self-estimation in multiattribute evaluation

Multiattribute analysis depends on measurement of values and weights. Unless these measures reflect the decision maker's true values and weights, the multiattribute formula may put a less-preferred alternative in first place. To avoid such disordinality requires stringent measurement conditions: First, the values and weights must be on linear (equal interval) or ratio (known zero) scales. Second, these scales must satisfy a condition of common unit across disparate attribute dimensions. Most methods of range adjustment beg both of these measurement questions. Functional measurement theory can solve both problems and so can be useful in multiattribute analysis. Past work has established the operation of a general cognitive algebra as an empirical reality. The averaging model, in particular, makes possible the definition and estimation of weights and values as distinct psychological parameters. It can also solve the problem of common unit. Cognitive algebra thus provides a grounded theoretical foundation on which to develop self-estimation methodology, in which decision makers provide direct estimates of their values and weights. The logic is straightforward. Functional measurement can analyze global judgments to obtain validated psychological scales. These scales may then be used as validational criteria for the self-estimates. Procedures to eliminate biases in the self-estimates can thus be tested and refined in well-learned multiattribute tasks, such as judgments of meals, in which global judgments are trustworthy. Once developed, such self-estimation procedures may be used with some confidence for general multiattribute analysis. A number of studies from 20-odd years of work on the theory of information integration are summarized to show good, although not unmixed promise for self-estimation.     

The detection of surface curvatures defined by optical motion.

The detectability of surface curvatures defined by optical motion was evaluated in three experiments. Observers accurately detected very small amounts of curvature in a direction perpendicular to the direction of rotation, but they were less sensitive to curvatures along the direction of rotation. Variations in either the number of points (between 91 and 9) or the number of views (from 15 to 2) had little or no effect on discrimination accuracy. The results of this study demonstrate impressive visual sensitivity to surface curvature. Several characteristics of this sensitivity to curvature are inconsistent with many computational models for deriving three-dimensional structure from motion.     

‘Healthy eating’ clinics in primary care: Programme intensity and patients' health beliefs

The primary care setting is seen by many to be at the forefront of the attempt to encourage people to follow healthier diets. Conducted in a single practice, the present study firstly considered the effectiveness of three ‘healthy eating’ clinics for patients found to have elevated cholesterol levels at screening. Through the use of a randomised trial, these patients received either basic dietay information or were invited back more frequently and requested to complete food diaries, half of which were then analysed through a computer program. At one year follow up the three programmes were found to have produced a 6.7% reduction in cholesterol levels. However, no differences were found between the three programmes. The study secondly examined a range of health belieji, based on the health belief model, as predictors of reductions in cholesterol levels. These were generally found to be poor predictors, with only the belief that one's diet is related to the chances of developing a number of major conditions and the perception of bam'ers dealing with confidence predicting these reductions. Finally, the case for incorporating self-efficacy beliefs into the healh belief model is outlined and the need for health counsellors to tailor their messages to the pre-existing beliefi and behaviours of patients is highlighted.     

Ordinal consistency and ordinal true scores

This paper argues that test data are ordinal, that latent trait scores are only determined ordinally, and that test data are used largely for ordinal purposes. Therefore it is desirable to develop a test theory based only on ordinal assumptions. A set of ordinal assumptions is presented, including an ordinal version of local independence. From these assumptions it is first shown that the gamma-correlation between two tests is the product of their gamma-correlations with the true latent order. The theory is generalized to allow for heterogeneous tests by defining a weighted average local independence. The tau-correlations between total score and the latent order can be found in both homogeneous and heterogeneous cases, and a system of differential item weighting to maximize the tau-correlation between weighted items and the latent order is provided. Thus a purely ordinal test theory seems possible.Part of this work was done while the author was a Visiting Fellow at Macquarrie University. The paper has benefitted from discussions with Professors Thomas J. Reynolds and Roderick P. McDonald and from the comments of several anonymous reviewers.