Some Cracks in the Empire of Chance (Flaws in the Foundations of Reliability)

Making quantified statements about the uncertainty associated with the lifelength of an item is one of the most fundamental tasks of reliability assessment. Most practitioners routinely do this using one of the several available statistical techniques. The purpose of this paper is two-fold. The first is to give the user an overview of the key tenets of two of the most commonly used parametric approaches. The second is to point out that these commonly used approaches involve strategies that are either ad hoc, or are in violation of some of the underlying tenets. A method that is devoid of logical flaws can be proposed, but this method is difficult to implement. The user must therefore resign to using that technique against which the fewest objections can be hurled.     

The Competent Primary Headteacher: Broadening the Management Competence Approach or Abandoning It?

Within management generally, and education management more specifically, there has been an almost continuous search for the key to effective management development. Generic occupational standards, generated by the Management Charter Initiative (MCI), are claimed to be applicable and transferable to any manager in any organization. Thus, a manager in a school would be expected to meet the same requirements as a manager in any other organization at the same management level. In the education world, both practitioners and theoreticians are sceptical about the competency approach. This article analyses the relevance of the management standards to primary headship by reporting on the experiences of six headteachers seeking NVQ management qualifications.     

Preparing for a world without markets: legitimising strategies of preppers

ABSTRACT

‘Prepping’ – the storing of food, water and weapons as well as the development of self-sufficiency skills for the purpose of independently surviving disasters – is an emerging market as well as an expression of generalised anxiety about existential threats (e.g. technological collapse and catastrophic climate change). Whilst accounts of eccentric prepping are common in mainstream media, there is little empirical investigation into how consumers imagine and prepare for a temporary or permanent halt to functioning market systems, and with it, a consumer society. A netnography of European preppers reveals prepping to be an anticipatory mode of practicing for a post-market, post-consumer society before it becomes a reality. We find that preparation is a struggle for cognitive legitimacy through four different modes: vulnerabilising the market, common-sensing market signals, othering civilian consumers and unblackboxing objects.     

A Paradigm for Masking (Camouflaging) Information

This is an expository paper. Here we propose a decision-theoretic framework for addressing aspects of the confidentiality of information problems in publicly released data. Our basic premise is that the problem needs to be conceptualized by looking at the actions of three agents: a data collector, a legitimate data user, and an intruder. Here we aim to prescribe the actions of the first agent who desires to provide useful information to the second agent, but must protect against possible misuse by the third. The first agent is under the constraint that the released data has to be public to all; this in some societies may not be the case.
A novel aspect of our paper is that all utilities—fundamental to decision making—are in terms of Shannon's information entropy. Thus what gets released is a distribution whose entropy maximizes the expected utility of the first agent. This means that the distribution that gets released will be different from that which generates the collected data. The discrepancy between the two distributions can be assessed via the Kullback–Leibler cross-entropy function. Our proposed strategy therefore boils down to the notion that it is the information content of the data, not the actual data, that gets masked. Current practice of "statistical disclosure limitation" masks the observed data via transformations or cell suppression. These transformations are guided by balancing what are known as "disclosure risks" and "data utility". The entropy indexed utility functions we propose are isomorphic to the above two entities. Thus our approach provides a formal link to that which is currently practiced in statistical disclosure limitation.     

Adversarial and Amiable Inference in Medical Diagnosis,Reliability and Survival Analysis

In this paper, we develop a family of bivariate beta distributions that encapsulate both positive and negative correlations, and which can be of general interest for Bayesian inference. We then invoke a use of these bivariate distributions in two contexts. The first is diagnostic testing in medicine, threat detection and signal processing. The second is system survivability assessment, relevant to engineering reliability and to survival analysis in biomedicine. In diagnostic testing, one encounters two parameters that characterize the efficacy of the testing mechanism: test sensitivity and test specificity. These tend to be adversarial when their values are interpreted as utilities. In system survivability, the parameters of interest are the component reliabilities, whose values when interpreted as utilities tend to exhibit co‐operative (amiable) behavior. Besides probability modeling and Bayesian inference, this paper has a foundational import. Specifically, it advocates a conceptual change in how one may think about reliability and survival analysis. The philosophical writings of de Finetti, Kolmogorov, Popper and Savage, when brought to bear on these topics constitute the essence of this change. Its consequence is that we have at hand a defensible framework for invoking Bayesian inferential methods in diagnostics, reliability and survival analysis. Another consequence is a deeper appreciation of the judgment of independent lifetimes. Specifically, we make the important point that independent lifetimes entail at a minimum, a two‐stage hierarchical construction.     

Many-valued Logic in Multistate and Vague Stochastic Systems

The state of the art in coherent structure theory is driven by two assertions, both of which are limiting: (1) all units of a system can exist in one of two states, failed or functioning; and (2) at any point in time, each unit can exist in only one of the above states. In actuality, units can exist in more than two states, and it is possible that a unit can simultaneously exist in more than one state. This latter feature is a consequence of the view that it may not be possible to precisely define the subsets of a set of states; such subsets are called vague . The first limitation has been addressed via work labeled 'multistate systems'; however, this work has not capitalized on the mathematics of many-valued propositions in logic. Here, we invoke its truth tables to define the structure function of multistate systems and then harness our results in the context of vagueness. A key contribution of this paper is to argue that many-valued logic is a common platform for studying both multistate and vague systems but, to do so, it is necessary to lean on several principles of statistical inference.     

Promoting shared health care decision making using the analytic hierarchy process

Recent developments in medical technology and bioethics have led to a shift in the traditional framework of physician–patient responsibility in health care decision making. Patients are increasingly participating in serious health care decisions, resulting in a “shared decision-making model“ that both patients and their doctors agree is a significant improvement over the traditional system in which a doctor served as the primary decision maker. However, patients are finding they need to develop strategies that allow them to understand and evaluate their health care options in a clear manner. T.L. Saaty’s “Analytic Hierarchy Process” (AHP) is a decision methodology that has been successfully applied to a wide variety of situations and has great potential as a methodology for improved shared health care decision making. This paper reports the results of an experimental use of AHP as a tool to facilitate shared decision making for two specific health care populations. Both groups of patients were deciding amongst their options in terms of two important elective health care procedures: estrogen replacement therapy and cosmetic eyelid surgery. After using AHP, the majority of both patients and physicians agreed that this technique improved physician–patient communication, thus greatly assisting shared health care decisions. When considering other criteria in addition to physician–patient communication, including the entire physician–patient relationship, the patients felt that AHP was preferable to the conventional doctor-patient mode of decision making.     

Cultural indicators in Abu Dhabi: theoretic framework and challenges for their building

Quality & Quantity - Evidence-based decision-making in Abu Dhabi cultural sector is increasingly being influenced by the development of data generation from a coordinated statistical system....