Accuracy of health-related quality of life assessment: what is the benefit of incorporating patients' preferences for domain functioning?

This study investigated the accuracy benefit of incorporating patients' preferences for domains of functioning into health-related quality of life (HRQOL) measurement. Using policy-capturing techniques, 102 medical outpatients judged the HRQOL of 16 scenarios describing varying levels of functioning in 3 domains. For each participant, regression analysis determined relative domain preferences and 2 decision models were built: one incorporating (preference-weighted) and one ignoring (equally weighted) domain preferences. To assess accuracy, the average proportion of judgment variance accounted for by each model was determined and both accounted for approximately 50%. However, for patients showing the greatest differences in importance across domains, the preference-weighted model was more accurate. Findings are discussed in the context of enhancing HRQOL assessment.

Validating a new process tracing method for decision making.

In this paper, we describe two experiments in which we assessed the validity of phased narrowing, a new process tracing technique designed to help researchers better understand multiattribute evaluation processes. Specifically, in Experiment 1 we examined the distribution of choices across successive decision stages and the attitudes and perceptions of the decision maker. In Experiment 2, we examined a variety of process data generated via a computerized information monitoring program called Mouse-Trace. Comparisons, in all cases, are made between experimental conditions that do and do not require decision makers to narrow their choices across successive stages. Taken together, the data indicate that there is little evidence to doubt the validity of a less restrictive version of phased narrowing which allows subjects to choose their own number of options to include at each stage. These results are encouraging for researchers who plan to use the technique to study decision making in its natural context.

A new laboratory method for altering positive affect.

This paper reports the development with 95 undergraduates of a new method for altering Positive Affect in the laboratory. The method consists of assigning persons to complete a boring task for a specific amount of time and shortly after beginning the task, informing them that the assigned time period has either been increased or reduced. The advantages of this method are that it is effective, relatively free of demand characteristics, ethical, fast to administer, and parallels "real world" experiences. In addition, this procedure seems to circumvent limitations of other mood-induction procedures.

Risky decision making and allocation of resources for leukemia and AIDS programs.

Traditional judgment and decision-making paradigms were expanded to include differential reactions to persons with leukemia or AIDS. Experiments 1 and 2 adopted Tversky and Kahneman's risky-decision-making task and found support for different value functions for the 2 patient groups when choosing between treatment programs. From these results, the subjective value of saving a fixed number of lives appears to be greater for persons with leukemia than for persons with AIDS. Experiment 3 provided additional data concerning differential perceptions of the causes of AIDS. This proved to be a useful means of classifying Ss who did and did not devalue the lives of persons with AIDS.

The need for process research on psychophysical judgment: comments on "Ratio and subtractive processes in psychophysical judgment" by Veit.

This article is a commentary on Veit's article "Ratio and Subtractive Processes in Psychophysical Judgment." Veit's article makes an important contribution to the area of psychophysical judgment by providing a systematic approach that combines measurement and psychological theory. Using multi-factor designs and a cross-task scale-invariance criterion, Veit shows how to concurrently examine the integration rule, response-transformation function, and psychophysical function for judgment tasks. The need to expand this methodology to further understand the operations and processes underlying psychophysical judgment is stressed in the present article, and an illustration involving feedback mechanisms is provided.

The processing of deviant information in prediction and evaluation.

Analyses of information integration and of retention were used to examine the processing of deviant information in prediction and evaluation tasks. Sets of test scores were presented serially for a group of hypothetical students, and subjects were asked to evaluate the performance of each student or predict each student's performance on a comprehensive final exam. An averaging model with greater weight for the more recent scores than for the earlier scores was supported for both types of task, but the recency was more pronounced in the prediction task. Weighting of deviant scores differed in the prediction and evaluation tasks. Significant discounting (underweighting) of deviant scores was obtained only in the prediction task, The ability to recall deviant scores on uncued tests of retention was higher in the prediction task than in the evaluation task. Prediction of future performance based on inconsistent measures of past performance thus appears to be an active process involving the discovery and discounting of unrepresentative information.

Invariance of the weight parameter in information integration.

The relative effect of each informational dimension in an information integration task is a joint function of its weight and the range of values over which it is varied. A method is developed for separating these two factors. Weights obtained by this method were compared across variations of stimulus range. Subjects rated the performance of students on the basis of midterm exam scores and final exam scores. For some subjects, the range of scores on the final exam was twice that on the midterm and the reverse was true for other subjects. An averaging model was shown to describe the results, and weights did not differ for different stimulus ranges. This was true for each of two instructional conditions: one in which a particular weighting strategy was prescribed and one in which there was no prescribed weighting. Students who were instructed to use a 2∶1 weighting were found to assign more than twice as much weight to the final as to the midterm.

Averaging processes in ratings and choices based on numerical information.

Ss were presented sets of numbers said to represent sample price information from grocery stores. Ss rated the relative desirability of shopping at each of a series of stores and were also asked to make paired-comparison preference choices. In Experiment I, some sets contained favorable information, some contained unfavorable information, and some contained neutral information added to the favorable or unfavorable information. The addition of neutral information led to a decrease in the polarity of responses. This is consistent with an averaging, but not an adding, formulation of how the information is integrated. In Experiment II, sets of favorable or unfavorable information varied in size and a set-size effect was obtained. The greater the amount of favorable or unfavorable information, the more extreme the response. This was accounted for by assuming that an initial neutral expectancy is averaged with the information presented.

Response scale effects and integration processes in the averaging of motor movements.

In two experiments Ss averaged pairs of fixed, linear motor movements. A production method of motor averaging was used in Exp. 1, and category scaling procedures were used in Exp. 2. Stimulus interaction effects were found in Exp. 1 but not in Exp. 2. Prior exposure to long or to short movements produced slight contrast effects in each experiment, but the nature of these effects differed between experiments. Results were interpreted within the context of averaging models of information integration theory. The implications of these models for theories of motor retention were discussed.

Learning effects in information integration: Manipulation of cue validity in an impression formation task.

In Stage 1, Ss predicted whether the majority of students in a previous study liked or disliked each of a series of hypothetical persons described by pairs of personality trait adjectives. One trait within each pair was highly polarized on a social desirability dimension, and the other was highly polarized on an intellectual desirability dimension. In Stage 2, new person descriptions were presented and Ss either predicted likabihty ratings for the reference group or gave their own personal ratings. Responses on Stage 2 varied as a function of feedback mampulations on Stage 1. The effect of feedback was to increase the relative weight of the dimension associated with reinforcement on Stage 1. This effect was more pronounced for Ss predcting the ratings of the reference group on Stage 2 than for Ss making personal ratings. These results illustrate how the weighting of information in an integration task can be manipulated through reinforcement contingencies.