Decision criteria do not shift: Reply to Treisman

Recently, we argued that the detection criterion representation of decision-making biases, embedded within the theory of signal detection, is empirically testable and has, in fact, been falsified by empirical results from visual discrimination experiments. Treisman (2002) attempts to show that there is an alternative interpretation of our results that could explain them without dropping the detection criterion construct. In lieu of attempting to fit the data with a model, however, he gives two kinds of theoretical examples, both involving manipulations of the spacing of criteria on a decision axis. The first example correctly predicts that the bias estimate we developed will be zero but does so by assuming zero spacing between some criteria (some rating responses are never used). We did not observe zero spacing between any criteria and did not perform any analyses on responses that never occurred. Moreover, this example does not explain why the upper-bound bias estimates that we obtained by combining results from two criteria placements were also trivially small. His second example predicts that the bias should have been detectable with sufficiently large sample sizes. In our experiments, the sample sizes were, in fact, quite large, large enough for the results to be consistent in 18 different experimental conditions. Finally, all of Treisman’s criteria placement examples also fail to explain the pronounced effects of base rates on the shapes of the rating ROC curves, and his suggestion that there are problems of logical interpretation with our proposed distribution model ignores the predictions of large classes of alternatives to detection theory, including the dynamic models of perception.     

Qualitative Health Research and the IRB: Answering the “So What?” with Qualitative Inquiry

Qualitative inquiry is increasingly used to foster change in health policy and practice. Research ethics committees often misunderstand qualitative inquiry, assuming its design can be judged by criteria of quantitative science. Traditional health research uses scientific realist standards as a means-to-an-end, answering the question “So what?” to support the advancement of practice and policy. In contrast, qualitative inquiry often draws on constructivist paradigms, generating knowledge either as an end-in-itself or as a means to foster change. When reviewers inappropriately judge qualitative inquiry, it restricts the ways health phenomena can be understood. Qualitative inquiry is necessary because it enables an understanding not possible within scientific explanation. When such research illuminates, it can also shed light onto the “So what?” In order to ensure an appraisal of qualitative inquiry congruent with its paradigmatic premises, we suggest the “Illumination Test,” met when findings foster rich understanding of phenomena, resulting in a reflective “aha!”     

Decision criteria do not shift: Commentary on Mueller and Weidemann (2008)

The effects of base rates and payoffs on the shapes of rating receiver operating characteristic curves are inconsistent with the basic assumptions of signal detection theory (SDT), in particular the notion of a shifting decision criterion. Mueller and Weidemann (2008) propose that these unexpected phenomena are not due to problems with the decision- criterion construct but are instead due to two compounded effects: instability of the decision criterion across trials, and even greater instability in the flanking criteria that determine which confidence rating will be reported. There are several problems with the authors’ decision-noise hypothesis. First, even if their hypothesis about decision noise were taken for granted, the key feature of the ratings data that rejects the SDT model would remain a mystery. Second, the same violations of SDT that are exhibited in the ratings paradigm are also exhibited in the yes-no detection task when response time is substituted for confidence as a basis for analysis. Finally, the decision-noise hypothesis predicts that sensitivity will increase when one source of this variation-the response on a previous trial-is controlled for. This prediction was consistently violated in both the yes-no and ratings conditions of Mueller and Weidemann’s experiment. In an Addendum, we respond to Weidemann and Mueller’s (2008) reply to this Comment.     

Body satisfaction, eating disorders and suicide ideation in an Internet sample of self-harmers reporting and not reporting childhood sexual abuse

This study examined differences between self-harmers who had and who had not been sexually abused in childhood with regards to other risk factors and associated behaviours commonly identified in the research literature as being related to self-harm. Participants (N = 113, mean age = 19.92 years) were recruited via self-harm Internet discussion groups and message boards, and completed a web questionnaire assessing measures of body satisfaction, eating disorders, childhood trauma and suicide ideation. Self-harmers who reported a history of childhood sexual abuse scored higher on measures of body dissatisfaction, eating disorders, suicide ideation, physical abuse, physical neglect, emotional abuse and emotional neglect. These findings implicate sexual abuse as a powerful traumatic event that can have severe repercussions on an individual, not only in terms of self-harming behaviour but also in terms of developing a wide range of maladaptive behaviours in conjunction with self-harm.     

More about linda or conjunctions in context

Abstract

Tversky and Kahneman (1982; 1983) reported that subjects rated the con junction of two events as more likely than one of the component events. This “conjunction effect” is an error in terms of formal probability, where the probability of more happening is always smaller than the probability of less. They explained this effect in terms of a “representativeness” heuristic. This paper focuses on the context of the problem and the suggestions implied by the questions in the task. The three studies reported here provide evidence that context effects and implicit suggestions alter subjects' judgements. Tvenky and Kahneman's models take no account of such factors. Two studies show that when implicit suggestions are reduced, subjects are much less prone to the conjunction “effect”. Subjects take being asked the question “Is person X a Y?”, as providing evidence that X may be Y.     

On the ‘undialectical’: normativity in Hegel

This paper addresses the question of normativity in Hegel by examining the role of ‘undialectical’ resistance to dialectical development. Beginning with a general overview of dialectical normativity and what it might mean to be ‘undialectical,’ the focus then shifts to a privileged example in Hegel’s writings: Sophocles’ Antigone. The central claim of the paper is the following: The very contradictions that fuel dialectical normativity can also trap individuals within an obsolete actuality, without immediate hope of escape. Indeed, the irreducible dependence of dialectical thinking upon the actions and decisions of individual consciousness expose it to the threat of continual stasis or regression. This ineliminable possibility of failure is what is here called the ‘undialectical’ moment of the dialectic, which Hegel understands rather as a negative condition of possibility of freedom and rationality.     

Illness representations in patients with multimorbid long-term conditions: qualitative study

Most research on illness representations explores how patients view single conditions, but many patients report more than one long-term condition (known as multimorbidity). It is not known how multimorbidity impacts on patient illness representations. This exploratory qualitative study examined patients' representations of multimorbid long-term conditions and sought to assess how models of illness representation might need modification in the presence of multimorbidity. We explored two major issues: (1) the impact of multimorbidity on patient representations of their individual conditions and (2) the representation of multimorbidity itself. Twenty eight adults with at least two long-term conditions (mean of 4) were interviewed. The presence of multimorbidity impacted on patient illness representations in relation to the dimensions of identity, perceived cause, coherence and consequences. Representations of multimorbidity itself concerned representations of the burden of medication and perceived priorities among conditions and synergies and antagonisms between conditions and their management. The results have implications for the measurement of multimorbidity (through scales such as the Illness Perception Questionnaire) and the use of illness representations in the design and delivery of interventions to improve health behaviour and outcomes of patients with multiple long-term conditions.     

Religion and bioethics: toward an expanded understanding

Before asking what U.S. bioethics might learn from a more comprehensive and more nuanced understanding of Islamic religion, history, and culture, a prior question is, how should bioethics think about religion? Two sets of commonly held assumptions impede further progress and insight. The first involves what “religion” means and how one should study it. The second is a prominent philosophical view of the role of religion in a diverse, democratic society. To move beyond these assumptions, it helps to view religion as lived experience as well as a body of doctrine and to see that religious differences and controversies should be welcomed in the public square of a diverse democratic society rather than merely tolerated.