Understanding Behavior in Escalation Situations

Everyday observation reveals that both individuals and organizations often become overly committed to losing courses of action; in a sense, throwing good money after bad. More than 10 years of research on this escalation problem shows that persistence is associated with at least four major clases of determinants: project, psychological, social, and organizational variables. The influence of these four sets of variables evolves over time, forming a dynamic model of behavior in escalation situations.

Lens model analysis of hemodynamic status in the critically ill

The lens model recently has been extended to consider multiple outcomes and sequential use of clinical information. The authors have used this extended model 1) to describe the relationship between clinical information and physicians' assessments of hemodynamic status, 2) to describe the empirical relationship between clinical information and physiologic measures of hemodynamic status, and 3) to compare physicians' use of information with its empirical utility. Physicians prospectively provided estimates of cardiac index and pulmonary capillary wedge pressure for 440 intensive care unit patients prior to right heart catheterization. The correlation between physicians' estimates and measured hemodynamic status was lower than that between clinical information and hemodynamic status (0.42 versus 0.67). Only 7% of physicians' judgement was related to subsequent ancillary testing. Empirically, subsequent ancillary testing contributed 30% to the explanation of hemodynamic status. The lens model describes limitations of physician judgement in estimating left ventricular function and helps explain how patient features relate to measured hemodynamic status.

Experimental Research on Jury Decision-Making

Because trial juries deliberate in secrecy, legal debates about jury functioning have relied heavily on anecdote and speculation. In recent years, investigators have begun to challenge many common assumptions about jury behavior. An important tool in this effort has been the mock jury experiment, in which research participants are randomly assigned to alternative trial conditions and asked to reach a verdict in a simulated case. Researchers have used mock jury experiments to test hypotheses about causal influences on jury behavior and to develop theoretical models of the jury deliberation process.

The Stanford Adolescent Heart Health Program

This study was designed to create, implement, and test a school-based multiple risk factor reduction program for high school students. All tenth graders in four senior high schools (N = 1447) from two school districts participated in the study. Within each district, one school was assigned at random to receive a special 20-session CVD risk reduction intervention and one school served as a control. The schools were matched for size and distribution of racial groups before randomization. At a two-month follow-up, knowledge gains were significantly greater for students in the treatment group on each of the risk factor domains tested: nutrition/diet (p less than 0.0001), physical activity (p less than 0.0001), and cigarette smoking (p less than 0.0001). Compared to controls, a higher proportion of those in the treatment group who were not exercising regularly at baseline, reported regular exercise at follow-up (p less than 0.0003). Almost twice as many baseline experimental smokers in the treatment group reported quitting at follow-up while only 5.6% of baseline experimental smokers in the treatment group graduated to regular smoking compared to 10.3% in the control group (p = 0.009). Students in the treatment group were more likely to report that they would choose heart healthy snack items (p less than 0.0001). Beneficial treatment effects were observed for resting heart rate (p less than 0.0001), BMI (p = 0.05), triceps skinfold thickness (p = 0.003), and subscapular skinfold thickness (p = 0.01). The results suggest that it is feasible to provide CVD risk reduction training to a large segment of the population through school-based primary prevention approaches.

Decision Making with Probability Forecasts of Rainfall

Decision making with probability forecasts of rainfall was investigated experimentally by considering three variables, i.e., the rainfall probability, the duration of being away from home, and the outdoor weather condition. 274 Japanese college students were asked to make decisions on the necessity for person A to take an umbrella with him under 16 different conditions. Analysis showed obviously that the necessity tended to increase as probability of rainfall rose, as duration became longer, and also as the outdoor weather was cloudy rather than clear. Discussion of these results considered recent studies of decision making and subjective probability.

Timed magnitude comparisons of numerical and nonnumerical expressions of uncertainty

Two experiments involving paired comparisons of numerical and nonnumerical expressions of uncertainty are reported. Subjects were timed under two opposing sets of instructions ("choose higher probability" vs. "choose lower probability"). Numerical comparisons were consistently faster and easier than their nonnumerical counterparts. Consistent distance and congruity effects were obtained, illustrating that both numerical and nonnumerical expressions of uncertainty contain subjective magnitude information, and suggesting that similar processes are employed in manipulating and comparing numerical and verbal terms. To account for the general pattern of results obtained, Holyoak's reference point model (1978) was generalized by explicitly including the vagueness of the nonnumerical expressions. This generalized model is based on the notion that probability expressions can be represented by membership functions (Wallsten, Budescu, Rapoport, Zwick, & Forsyth, 1986) from which measures of location for each word, and measures of overlap for each pair can be derived. A good level of fit was obtained for this model at the individual level.

Improving the accuracy of clinical judgment

Diagnostic reasoning in psychiatry is as intricate as it is risky (Elstein et al. 1978; Fitzhenry-Coor 1986; Fitzhenry-Coor and Nurcombe 1983; Gauron and Dickinson 1965; Sandifer et al. 1970; Kendell 1973; Nurcombe and Fitzhenry-Coor 1982). During the clinical encounter, the clinician elicits, notes, and verifies pertinent clinical cues. Early in the encounter, from an assembled but incomplete pattern of data, an array of diagnostic hypotheses is generated. Subsequently, in the light of evidence systematically gathered, each diagnostic possibility is progressively refined or deleted until the diagnostic conclusion is reached. The validity of the clinical endeavor, thus, depends upon the pertinence of the hypotheses generated, for it is upon them that deductive reasoning will hinge. It also depends upon the reliability of the history, signs, and investigations that constitute the evidence gathered for or against each of the hypotheses. The purpose of this paper is to propose systematic strategies based on principles of probability and empirical research, with the aim of sharpening clinical reasoning.

Stressor frequency, tension, tiredness and coping: some measurement issues and a comparison across nursing groups

In nursing research a number of approaches have been adopted when measuring the relationship between stressor and stress. However, despite thorough questionnaire development, excess demand, that is the extent to which the situation actually taxes the resources of the nurse, is measured more by implications than by presence. By combining different facets of demand and by measuring them in conjunction with one another this research revealed the extent to which the demands of frequently occurring situations actually taxed the resources of the nurse; provided a procedure for more specifically investigating the relationship between stressor frequency and response and considered these findings in terms of different types of nurses (enrolled, staff, charge) and the coping strategies used. The results were discussed in terms of measurement, training, available resources, coping and interventions.

Health education: special issues for older adults

The older adult population in the United States has grown substantially since the turn of the century. With extended longevity and the relatively good functional status of most older adults, prevention programs that identify and intervene on risk factors in older adults may be an effective means to dealy ill health. The availability of data to guide both the selection and evaluation of prevention services for older adults, however, is strikingly limited in virtually all areas. Until recently, all persons over the age of 65 were treated as a single category of older adults although the older population is very heterogeneous. Most agree that prevention and education for this age group should focus on the prevention of disease, maintenance of existing abilities, and on prevention of deterioration of impairments that result in dysfunction or handicap. The most effective methods for developing behavioral intervention strategies may result from an integration of the behavioral diagnostic framework and current value expectancy and social learning theories. Health education interventions based on these strategies can be very effective in older age groups in terms of both improving adherence behavior with therapeutic and prevention intervention, and potentially in reducing morbidity and excess mortality.