Problems with using mechanisms to solve the problem of extrapolation

Proponents of evidence-based medicine and some philosophers of science seem to agree that knowledge of mechanisms can help solve the problem of applying results of controlled studies to target populations (‘the problem of extrapolation’). We describe the problem of extrapolation, characterize mechanisms, and outline how mechanistic knowledge might be used to solve the problem. Our main thesis is that there are four often overlooked problems with using mechanistic knowledge to solve the problem of extrapolation. First, our understanding of mechanisms is often (and arguably, likely to remain) incomplete. Secondly, knowledge of mechanisms is not always applicable outside the tightly controlled laboratory conditions in which it is gained. Thirdly, mechanisms can behave paradoxically. Fourthly, as Daniel Steel points out, using mechanistic knowledge faces the problem of the ‘extrapolator’s circle’. At the same time, when the problems with mechanistic knowledge have been addressed, such knowledge can and should be used to mitigate (nothing can entirely solve) the problem of extrapolation.     

Associative asymmetry in probed recall of serial lists

For pairs of meaningful items (e.g., words), recall accuracy is nearly identical for forward and backward probes. That is, after studying an A-B pair, subjects can recall A given B as well as they can recall B given A (Kahana, 2002). To assess whether this symmetry property is unique to pairs, we investigated the effects of study direction on probed recall of word triples and serial lists. Two experiments revealed a forward-recall advantage in both triples and serial lists. In addition, compound cues produced better recall than did single-item adjacent cues, which, in turn, produced better recall than did remote cues. These findings suggest a discontinuity between the associative processes supporting memory for pairs and those supporting memory for sequences of three or more items.     

Health service use costs by personality disorder following specialist and nonspecialist treatment: a comparative study

The impact of specialist psychosocial treatment on health service use costs by patients with personality disorder is not yet sufficiently documented. In this prospective study we compare patterns of health service costs by three groups of people with personality disorder treated in a hospital-based program (IPP), a step down program (SDP), and a general psychiatric program (GPP). Total service use costs at follow up, compared with intake costs, showed that significantly higher savings were achieved by SDP and IIP compared with GPP. Cost reductions in SDP were significantly greater than in IPP. Significant cost reductions were found between treatment programs in social worker and community psychiatric nursing and psychotherapy. The cost-effectiveness of the two specialist treatment programs was indicated by the significant association between total cost reduction and clinical outcome in GPP and IPP, but not in GPP. The effect of Major Depression and Borderline Personality Disorder on health service use alone and in combination was also investigated. The finding that Major Depression was found to be more significantly associated with higher health service use costs than Borderline Personality Disorder is discussed.     

Measures of Criminal Attitudes and Associates (MCAA): development,factor structure,reliability, and validity

Recent meta-analysis has demonstrated that attitudes and associates are among the best predictors of antisocial behavior. Despite this finding, there are few psychometrically developed and validated measures of criminal and antisocial attitudes and associates. This study reviews the theoretical and empirical development of the Measures of Criminal Attitudes and Associates (MCAA), which is composed of two parts. Part A is a quantified self-report measure of criminal friends. Part B contains four attitude scales: Violence, Entitlement, Antisocial Intent, and Associates. The MCAA showed reasonable reliability (internal consistency and temporal stability) and appropriate convergent and discriminant validity. Criterion validity was evidenced in the scale's relationship with criminal history variables, and a factor analysis confirmed the four distinct scale domains.     

Reconsidering Relativistic Causality

I discuss the idea of relativistic causality, i.e., the requirement that causal processes or signals can propagate only within the light‐cone. After briefly locating this requirement in the philosophy of causation, my main aim is to draw philosophers’ attention to the fact that it is subtle, indeed problematic, in relativistic quantum physics: there are scenarios in which it seems to fail.

I set aside two such scenarios, which are familiar to philosophers of physics: the pilot‐wave approach, and the Newton–Wigner representation. I instead stress two unfamiliar scenarios: the Drummond–Hathrell and Scharnhorst effects. These effects also illustrate a general moral in the philosophy of geometry: that the mathematical structures, especially the metric tensor, that represent geometry get their geometric significance by dint of detailed physical arguments.     

Knowing against the odds

We present and discuss a counterexample to the following plausible principle: if you know that a coin is fair, and for all you know it is going to be flipped, then for all you know it will land tails.     

Sleeping beauty should be imprecise

The traditional solutions to the Sleeping Beauty problem say that Beauty should have either a sharp 1/3 or sharp 1/2 credence that the coin flip was heads when she wakes. But Beauty’s evidence is incomplete so that it doesn’t warrant a precise credence, I claim. Instead, Beauty ought to have a properly imprecise credence when she wakes. In particular, her representor ought to assign \(R(H\!eads)=[0,1/2]\) . I show, perhaps surprisingly, that this solution can account for the many of the intuitions that motivate the traditional solutions. I also offer a new objection to Elga’s restricted version of the principle of indifference, which an opponent may try to use to collapse the imprecision.