Risk homeostasis theory in simulated environments

This thesis has two aims. First, it sets out to develop an alternative methodology for the investigation of risk homeostasis theory (RHT). It is argued that the current methodologies of the pseudo-experimental design and post hoc analysis of road-traffic accident data both have their limitations, and that the newer 'game' type simulation exercises are also, but for different reasons, incapable of testing RHT predictions. The alternative methodology described here is based on the simulation of physical risk with intrinsic reward rather than a 'points pay-off'. The second aim of the thesis is to examine a number of predictions made by RHT through the use of this alternative methodology. Since the pseudo-experimental design and post hoc analysis of road-traffic data are both ill-suited to the investigation of that part of RHT which deals with the role of utility in determining risk-taking behaviour in response to a change in environmental risk, and since the concept of utility is critical to RHT, the methodology reported here is applied to the specific investigation of utility. Attention too is given to the question of which behavioural pathways carry the homeostasis effect, and whether those pathways are 'local' to the nature of the change in environmental risk. It is suggested that investigating RHT through this new methodology holds a number of advantages and should be developed further in an attempt to answer the RHT question. It is suggested too that the methodology allows RHT to be seen in a psychological context, rather than the statistical context that has so far characterised its investigation. The experimental findings reported here are in support of hypotheses derived from RHT and would therefore seem to argue for the importance of the individual and collective target level of risk, as opposed to the level of environmental risk, as the major determinant of accident loss.

Effect of delay of first interview and repetition of interview on accuracy and confidence of recall of a flashbulb -type memory

Hearing of the news of the death of Diana, Princess of Wales, in a traffic accident, is taken as an analogue for being a percipient but uninvolved witness to a crime, or a witness to another person's sudden confession to some illegal act. This event (known in the literature as a “reception event”) has previously been hypothesized to cause one to form a special type of memory commonly known as a “flashbulb memory” (FB) (Brown and Kulik, 1977). FB's are hypothesized to be especially resilient against forgetting, highly detailed including peripheral details, clear, and inspiring great confidence in the individual for their accuracy. FB's are dependent for their formation upon surprise, emotional valence, and impact, or consequentiality to the witness of the initiating event. FB's are thought to be enhanced by frequent rehearsal. FB's are very important in the context of criminal investigation and litigation in that investigators and jurors usually place great store in witnesses, regardless of their actual accuracy, who claim to have a clear and complete recollection of an event, and who express this confidently. Therefore, the lives, or at least the freedom, of criminal defendants, and the fortunes of civil litigants hang on the testimony of witnesses professing to have FB's. ^ In this study, which includes a large and diverse sample (N = 305), participants were surveyed within 2–4 days after hearing of the fatal accident, and again at intervals of 2 and 4 weeks, 6, 12, and 18 months. Contrary to the FB hypothesis, I found that participants' FB's degraded over time beginning at least as early as two weeks post event. At about 12 months the memory trace stabilized, resisting further degradation. Repeated interviewing did not have any negative affect upon accuracy, contrary to concerns in the literature. Analysis by correlation and regression indicated no effect or predictive power for participant age, emotionality, confidence, or student status, as related to accuracy of recall; nor was participant confidence in accuracy predicted by emotional impact as hypothesized. Results also indicate that, contrary to the notions of investigators and jurors, witnesses become more inaccurate over time regardless of their confidence in their memories, even for highly emotional events. ^

Rutiner i omvårdnad på intensivvårdavdelning av hjärnskadade patienter : Intervjustudie

Bakgrund: Traumatisk hjärnskada (THS) orsakas av våld mot huvud i samband med fallolyckor eller trafikolyckor. Varje år söker 20 000 personer vård på grund av skallskador. Vården för traumatiskt hjärnskadade patienter i Sverige skiljer sig åt, mycket beroende på avstånden som finns till specialistsjukhus, tiden och rätta åtgärder är avgörande faktorer för denna patientgrupp. Syfte: Att undersöka vikten och intensivvårdssjuksköterskors behov av rutiner i samband med vård av patienter med hjärnskador på allmänintensivvårdsavdelningar och på neurointensivvårdavdelningar. Metod: Kvalitativ studie med fokusgruppsintervjuer av tio intensivvårdsjuksköterskor som arbetar på en allmänintensivvårdsavdelning (IVA) och specialistneurointensivvårdavdelningen (NIVA). Resultat: På NIVA finns väl inarbetade rutiner och tydliga riktlinjer nedskrivna. Sjuksköterskornas upplevelse var att det fanns tillräckligt med rutiner, men några rutiner kunde utvecklas. På IVA fanns det inga nedskrivna riktlinjer och inga tydliga rutiner för att vårda denna patientgrupp. Vården och kontrollerna ordinerades av läkare som är i tjänst. Slutsats: Vården kring hjärnskadade patienter är ytterst viktigt då man ständigt måste förebygga sekundära skador/insulter. Rutiner är väl inarbetade på specialistsjukhuset, men vården börjar först på hemsjukhuset på IVA där tydliga rutiner och riktlinjer saknas.

The effect of truck size and weight on accident experience and traffic operations. Volume 1: executive summary. Final report.

Federal Highway Administration, Washington, D.C.

The effect of truck size and weight on accident experience and traffic operations. Volume II: traffic operations. Final report.

Federal Highway Administration, Washington, D.C.

The effect of truck size and weight on accident experience and traffic operations. Volume III: accident experience of large trucks. Final report.

Federal Highway Administration, Washington D.C.

Tri-level study: modification. Task 5: an examination of driver characteristics and collision producing errors of accident and traffic violation repeaters. Final report.

National Highway Traffic Safety Administration, Washington, D.C.

The effect of truck size and weight on accident experience and traffic operations. Volume IV: truck exposure classification by size and weight. Final report.

Federal Highway Administration, Washington, D.C.

National Accident Sampling System - NASS - report on traffic accidents and injuries for 1979.

Mode of access: Internet.

National Accident Sampling System 1981 - a report on traffic accidents and injuries in the U.S. collected in NASS in the year 1981.

Mode of access: Internet.

National Accident Sampling System 1983 - a report on traffic accidents and injuries in the U.S.

Mode of access: Internet.

National Accident Sampling System 1984 - a report on traffic accidents and injuries in the U.S.

Mode of access: Internet.

National Accident Sampling System 1985 - a report on traffic accidents and injuries in the U.S.

Mode of access: Internet.

National Accident Sampling System 1986 - a report on traffic crashes and injuries in the U.S.

Mode of access: Internet.

National Accident Sampling System 1982 - a report on traffic accidents and injuries in the U.S. collected in NASS in the year 1982.

Mode of access: Internet.