Credibility Indicators Research Articles

Criteria by which to evaluate risk-adjusted outcomes programs in cardiac surgery

Risk adjustment models for hospitalized patients are most advanced for the assessment of the clinical outcome of cardiac procedures, and for coronary artery bypass grafting in particular. The goal of being able to use outcomes as a credible indicator of quality of care has stimulated the development of several programs that use reliable, valid patient data collected during the surgical episode to adjust outcomes for the severity of illness. Several criteria that are useful in the assessment of risk adjustment methods for outcome and quality-of-care investigations are discussed in detail and five of these programs are compared. The programs have more similarities than differences and identify many of the same patient characteristics predictive of a higher likelihood of mortality in the period immediately after operation. Whether persistent differences in mortality after risk adjustment across institutions or Individual surgeons, or both, may ultimately be attributed to the process and structure of care needs further study and investigation. Similar methods should be applied to other outcomes of importance to patients, their families, and their physicians, such as surgically related morbidity, functional status, quality of life, costs, and patient-reported perceptions of the nontechnical aspects of their care.

Hydraulic bulging of near-isotropic sheet metal through an elliptical aperture

Hydraulic bulging tests through various elliptical apertures, with a manual control procedure for control of straining rate, were performed on near-isotropic sheet steel. Considering bulging as an ideal straining (rather than stressing) process, a relatively simple formulation for representative flow stress was devised and compared with other modes of calculation. After analysis of experimental error and sources of variation, a combination of uniaxial and biaxial tension data yielded an apparently uniform stress-strain relationship with a more credible indication of strain-hardening propensity than that obtained from uniaxial tests.

Role of Neutron Bubble Dosemeters

Abstract Bubble dosemeters may determine whether routine dosimetry is required, because they are a credible indicator of the presence or absence of neutrons even in strong gamma ray fields. They can be used, as pocket ion chambers are, to complement a primary dosemeter. They are small and need no phantom to measure neutrons from thermal to 25 MeV, so they can map fields varying rapidly with distance. Spectrometers are made from bubble devices(s) with various thresholds. Bubble dosemeters with electronic counters may serve as area monitors. Such roles use the bubble device's high sensitivity, immediate results, freedom from interference, and flat energy response while avoiding its weaknesses in dynamic range, lifetime, and variation of response with temperature.

Students' R]eactions to Teachers' E]valuations: The Unique Impact of Negative Feedback1

This study attempts to identify some of the processes mediating self‐fulfilling prophecies in the classroom. Specifically, we hypothesized that negative feedback conveyed by teachers would influence students' p]erceptions of how the teacher viewed their success/failure, effort, ability and task difficulty more than positive feedback. In response to college students' s]core on an anagrams test, a (confederate) teacher expressed either positive, negative or no evaluative feedback. Questionnaires assessed students' s]elf‐perceptions and perceptions of the teacher's evaluations of them. Consistent with our hypotheses, negative feedback was seen as a more credible indicator of the teacher's evaluation than positive feedback. Furthermore, negative feedback led students to believe that the teacher held an extremely unfavorable but inaccurate impression of their effort and ability and that the teacher underestimated the difficulty of the task. There were few differences between the effects of positive feedback and no feedback, and there were no significant effects on self‐perceptions. These findings suggest new insights into negativity effects in evaluations and into the mechanisms underlying self‐fulfilling prophecies.

Smoking artifacts as indicators of homophily, attraction, and credibility

The purpose of the study was to determine whether smoking artifacts (pipe, cigar, cigarette, and control) would have an influence upon the perceptions of a source's homophily, interpersonal attraction, and credibility. Using the same source, the researchers found a number of significant differences based upon the type of smoking artifact used and the sex of the subject. Suggestions for future research are also made by the researchers.