A Bayesian network (BN) is a graphical model of uncertainty that is especially well suited to legal arguments. It enables us to visualize and model dependencies between different hypotheses and pieces of evidence and to calculate the revised probability beliefs about all uncertain factors when any piece of new evidence is presented. Although BNs have been widely discussed and recently used in the context of legal arguments, there is no systematic, repeatable method for modeling legal arguments as BNs. Hence, where (...) BNs have been used in the legal context, they are presented as completed pieces of work, with no insights into the reasoning and working that must have gone into their construction. This means the process of building BNs for legal arguments is ad hoc, with little possibility for learning and process improvement. This article directly addresses this problem by describing a method for building useful legal arguments in a consistent and repeatable way. The method complements and extends recent work by Hepler, Dawid, and Leucari (2007) on object-oriented BNs for complex legal arguments and is based on the recognition that such arguments can be built up from a small number of basic causal structures (referred to as idioms). We present a number of examples that demonstrate the practicality and usefulness of the method. (shrink)
The problem of the relationship between actors and the social structures in which they are embedded is central to sociological theory. This paper suggests that the "new institutionalist" focus on fields, domains, or games provides an alternative view of how to think about this problem by focusing on the construction of local orders. This paper criticizes the conception of actors in both rational choice and sociological versions of these theories. A more sociological view of action, what is called "social skill," (...) is developed. The idea of social skill originates in symbolic interactionism and is defined as the ability to induce cooperation in others. This idea is elaborated to suggest how actors are important to the construction and reproduction of local orders. I show how its elements already inform existing work. Finally, I show how the idea can sensitize scholars to the role of actors in empirical work. (shrink)
The conflict between agency and stakeholder theories of the firm has long been entrenched in organizational and management literature. At the core of this debate are two competing views of the firm in which assumptions and process contrast each other so sharply that agency and stakeholder views of the firm are often described as polar opposites. The purpose of this paper is to show how agency theory can be subsumed within a general stakeholder model of the firm. By analytically deconstructing (...) the assumptions of agency theory, it is argued that agency theory: must include a recognition of stakeholders; requires a moral minimum to be upheld, which places four moral principles above the interests of any stakeholders, including shareholders; consists of contradictory assumptions about human nature and which give rise to the equally valid assumptions of trust, honesty and loyalty to be infused into the agency relationship. In this way, stakeholder theory is argued to be the logical conclusion of agency theory. Empirical hypotheses are presented as a means to substantiate this claim. (shrink)
It is well known that Bayes’ theorem (with likelihood ratios) can be used to calculate the impact of evidence, such as a ‘match’ of some feature of a person. Typically the feature of interest is the DNA profile, but the method applies in principle to any feature of a person or object, including not just DNA, fingerprints, or footprints, but also more basic features such as skin colour, height, hair colour or even name. Notwithstanding concerns about the extensiveness of databases (...) of such features, a serious challenge to the use of Bayes in such legal contexts is that its standard formulaic representations are not readily understandable to non-statisticians. Attempts to get round this problem usually involve representations based around some variation of an event tree. While this approach works well in explaining the most trivial instance of Bayes’ theorem (involving a single hypothesis and a single piece of evidence) it does not scale up to realistic situations. In particular, even with a single piece of match evidence, if we wish to incorporate the possibility that there are potential errors (both false positives and false negatives) introduced at any stage in the investigative process, matters become very complex. As a result we have observed expert witnesses (in different areas of speciality) routinely ignore the possibility of errors when presenting their evidence. To counter this, we produce what we believe is the first full probabilistic solution of the simple case of generic match evidence incorporating both classes of testing errors. Unfortunately, the resultant event tree solution is too complex for intuitive comprehension. And, crucially, the event tree also fails to represent the causal information that underpins the argument. In contrast, we also present a simple-to-construct graphical Bayesian Network (BN) solution that automatically performs the calculations and may also be intuitively simpler to understand. Although there have been multiple previous applications of BNs for analysing forensic evidence—including very detailed models for the DNA matching problem, these models have not widely penetrated the expert witness community. Nor have they addressed the basic generic match problem incorporating the two types of testing error. Hence we believe our basic BN solution provides an important mechanism for convincing experts—and eventually the legal community—that it is possible to rigorously analyse and communicate the full impact of match evidence on a case, in the presence of possible errors. (shrink)
When the benefits of surgery do not outweigh the harms or where they do not clearly do so, surgical interventions become morally contested. Cutting to the Core examines a number of such surgeries, including infant male circumcision and cutting the genitals of female children, the separation of conjoined twins, surgical sex assignment of intersex children and the surgical re-assignment of transsexuals, limb and face transplantation, cosmetic surgery, and placebo surgery.
In a recent paper “Safety, Sensitivity, and Differential Support”, Jose Zalabardo argues that :141–153, 1999) sensitivity can be differentially supported as the correct requirement for propositional knowledge. Zalabardo argues that safety fails to dominate sensitivity; specifically: some cases of knowledge failure can only be explained by sensitivity. In this paper, I resist Zalabardo’s conclusion that domination failure confers differential support for sensitivity. Specifically, I argue that counterexamples to sensitivity undermine differential support for sensitivity. Using Zalabardo’s modal framework, I consider a (...) less demanding modal condition, what I call weak sensitivity, and I explain how weak sensitivity avoids an influential counterexample to sensitivity. However, I argue that we can subvert that counterexample only by abandoning Zalabardo’s case for domination failure. So either way, we cannot differentially support sensitivity. (shrink)
This paper aims to show how medical scientists may use metaphor in ways closely parallel to poets. Those who believe metaphor has any role at all in science may describe its use in various ways. Associationists think metaphors are based upon likenesses, and collapse the notions of model and metaphor together. But, as an example from the work of Louis Pasteur suggests, metaphor need not be based upon likenesses. Rather it may play a role in making possible a model'sexplanatory significance. (...) Models may presuppose metaphors. The Pasteur example also suggests metaphor may play a part in creating likenesses through its role in classification and reclassification. It is in these ways that the use of metaphor in medical science most closely parallels that in poetry. (shrink)
Objectives: To discover the current state of opinion and practice among doctors in Victoria, Australia, regarding end-of-life decisions and the legalisation of voluntary euthanasia. Longitudinal comparison with similar 1987 and 1993 studies.Design and participants: Cross-sectional postal survey of doctors in Victoria.Results: 53% of doctors in Victoria support the legalisation of voluntary euthanasia. Of doctors who have experienced requests from patients to hasten death, 35% have administered drugs with the intention of hastening death. There is substantial disagreement among doctors concerning the (...) definition of euthanasia.Conclusions: Disagreement among doctors concerning the meaning of the term euthanasia may contribute to misunderstanding in the debate over voluntary euthanasia. Among doctors in Victoria, support for the legalisation of voluntary euthanasia appears to have weakened slightly over the past 17 years. Opinion on this issue is sharply polarised. (shrink)
In response to recent corporate ethical and financial disasters there has been increased pressure on business schools to improve their teaching of corporate ethics. Accreditation bodies, such as the Association to Advance Collegiate Schools of Business, now require member institutions to develop the ethical awareness of business students, either through a dedicated subject or an integrated coverage of ethics across the curriculum. This paper describes an institutional approach to the incorporation of a comprehensive multi-disciplinary ethics framework into the business curriculum. (...) We discuss important implications for the assessment of ethics within institutional assurance practices, and address critical issues related to the support of academics whenrequired to incorporate new ethics material within their subject which may be outside their field of expertise. As an example, the successful application of the framework within the marketing discipline is presented and discussed. (shrink)
In this review, we discuss how two evolutionarily conserved pathways at the interface of DNA replication and repair, template switching and break-induced replication, lead to the deleterious large-scale expansion of trinucleotide DNA repeats that cause numerous hereditary diseases. We highlight that these pathways, which originated in prokaryotes, may be subsequently hijacked to maintain long DNA microsatellites in eukaryotes. We suggest that the negative mutagenic outcomes of these pathways, exemplified by repeat expansion diseases, are likely outweighed by their positive role in (...) maintaining functional repetitive regions of the genome such as telomeres and centromeres. Break-induced replication and template switching are conserved mechanisms of replication fork restart. They do not cause microsatellite instability in prokaryotes, but promote repeat expansion in eukaryotes. We suggest that TS and BIR persisted in eukaryotes despite their mutagenic potential because they help maintain long repetitive telomeres and centromeres. (shrink)
Using the Liber Pontificalis and Liber Pontificalis ecclesiae Ravennatis, the official records of the churches of Rome and Ravenna, the author surveys the evidence for episcopal involvement in the many crises that impinged on these two important cities and on Byzantine Italy generally in the fifth and sixth centuries. Six categories of crisis are investigated. By a comparison of the two sources Neil examines the defining differences between Roman and Ravennan approaches to crisis management in Byzantine Italy.
As is clear to any user of software, quality control of software has not reached the same levels of sophistication as it has with traditional manufacturing. In this paper we argue that this is because insufficient thought is being given to the methods of reasoning under uncertainty that are appropriate to this domain. We then describe how we have built a large-scale Bayesian network to overcome the difficulties that have so far been met in software quality control. This exploits a (...) number of recent advances in tool support for constructing large networks. We end the paper by describing how the network was validated and illustrate the range of reasoning styles that can be modelled with this tool. (shrink)