What Made the Ratman Sick?

Articl

Rigour versus the need for evidential diversity

This paper defends the need for evidential diversity and the mix of methods that that can in train require. The focus is on causal claims, especially ‘singular’ claims about the effects of causes in a specific setting—either what will happen or what has happened. I do so by offering a template that categorises kinds of evidence that can support these claims. The catalogue is generated by considering what needs to happen for a causal process to carry through from putative cause at the start to the targeted effect at the end. The usual call for mixed methods focusses on a single overall claim and argues that we increase certainty by the use of different methods with compensating strengths and weaknesses. My proposals instead focus on the evidence that supports the great many subsidiary claims that must hold if the overall one is to be true. As is typical for singular causal claims, the mix of methods that will generally be required to collect the kinds of evidence I urge will usually have little claim to the kind of rigour that is now widely demanded in evidencing causal claims, especially those for policy/treatment effectiveness. So I begin with an exploration of what seems to be intended by ‘rigour’ in such discussions, since it is seldom made clear just what makes the favoured methods especially rigorous. I then argue that the emphasis on rigour can be counterproductive. Rigour is often the enemy of evidential diversity, and evidential diversity—lots of it—can make for big improvements in the reliability of singular causal predictions and post hoc evaluations. I illustrate with the paragon of rigour for causal claims, randomised controlled trials (RCTs), rehearsing at some length what they can and cannot do to make it easier to assess the importance of rigour in warranting singular causal claims

Evidence alone is not enough: policymakers must be able to access relevant evidence if their policy is to work

It is not enough to look for evidence of a previous policy success. Jeremy Hardie and Nancy Cartwright argue that exactly what evidence is needed, and of what, is the key question that needs to be asked for making real evidence-based social policy interventions

Objectivity and Intellectual Humility in Scientific Research: They’re Harder Than You Think

We begin from the assumption that where scientific research will predictably be used to affect things of moral significance in the world, you have a special duty, a duty of care, to ‘get it right’. This, we argue, requires a special kind of objectivity, ‘objectivity to be found’. What is it that’s to be found? In any kind of scientific endeavour, you should make all reasonable efforts to find the right methods to get the right results to serve the purposes at stake and neither exaggerate nor underestimate the credibility of what you have done. That, we take it, is what in this context constitutes objectivity and intellectual humility. But where your results will affect the world, you have a more demanding duty: a duty to ‘get it right’ about the purposes the endeavour should serve. Often the most morally significant purposes are those that ‘go without saying’ and because they are not said, we can too easily overlook them, sometimes at the cost even of human lives. We illustrate this with the example of the Vajont dam design and the flawed modelling that resulted in the Hillsborough football disaster

XIII FUNDAMENTALISM vs THE PATCHWORK OF LAWS

For realism. A number of years ago I wrote How the Laws of Physics Lie. That book was generally perceived to be an attack on realism. Nowadays I think that I was deluded about the enemy: it is not realism but fundamentalism that we need to combat. My advocacy of realism-local realism about a variety of different kinds of knowledge in a variety of different domains across a range of highly differentiated situations-is Kantian in structure. Kant frequently used what should be a puzzling argument form to establish quite abstruse philosophical positions (0): We have X-perceptual knowledge, freedom of the will, whatever. But without 0 (the transcendental unity of apperception, or the kingdom of ends) X would be impossible, or inconceivable. Hence 0. The objectivity of local knowledge is my 0; X is the possibility of planning, prediction, manipulation, control, and policy setting. Unless our claims about the expected consequences of our actions are reliable, our plans are for nought. Hence knowledge is possible. What might be found puzzling about the Kantian argument form are the X's from which it starts. These are generally facts that appear in the clean and orderly world of pure reason as refugees with neither proper papers nor proper introductions, of suspect worth and suspicious origin. The facts that I take to ground objectivity are similarly alien in the clear, well-lighted streets of reason, where properties have exact boundaries, rules are unambiguous, and behaviour is precisely ordained. I know that I can get an oaktree from an acorn, but not from a pine-cone; that nurturing will make my child more secure; that feeding the hungry and housing the homeless will make for less misery; and that giving more smear tests will lessen the incidence of vaginal cancer. Getting closer to physics, which is ultimatel

Mechanisms, laws and explanation

Mechanisms are now taken widely in philosophy of science to provide one of modern science’s basic explanatory devices. This has raised lively debate concerning the relationship between mechanisms, laws and explanation. This paper focuses on cases where a mechanism gives rise to a ceteris paribus law, addressing two inter-related questions: (1) What kind of explanation is involved? and (2) What is going on in the world when mechanism M affords behavior B described in a ceteris paribus law? We explore various answers offered by ‘new mechanists’ and others before setting out and explaining our own answers: (1) mechanistic explanations are a species of old-fashioned covering-law explanation and this often accounts in part for their explanatory power; and (2) B is what it takes for some set of principles that govern the features of M’s parts in their arrangement in M all to be instanced together

Are NH3_3 and CO2_2 ice present on Miranda?

Published near-infrared spectra of the four largest classical Uranian satellites display the presence of discrete deposits of CO$_2$ ice, along with subtle absorption features around 2.2 $\mu$m. The two innermost satellites, Miranda and Ariel, also possess surfaces heavily modified by past endogenic activity. Previous observations of the smallest satellite, Miranda, have not detected the presence of CO$_2$ ice, and a report of an absorption feature at 2.2 $\mu$m has not been confirmed. An absorption feature at 2.2 $\mu$m could result from exposed or emplaced NH$_3$- or NH$_4$-bearing species, which have a limited lifetime on Miranda's surface, and therefore may imply that Miranda's internal activity was relatively recent. In this work, we analyzed near-infrared spectra of Miranda to determine whether CO$_2$ ice and the 2.2-$\mu$m feature are present. We measured the band area and depth of the CO$_2$ ice triplet (1.966, 2.012, and 2.070 $\mu$m), a weak 2.13-$\mu$m band attributed to CO$_2$ ice mixed with H$_2$O ice, and the 2.2-$\mu$m band. We confirmed a prior detection of a 2.2-$\mu$m band on Miranda, but we found no evidence for CO$_2$ ice, either as discrete deposits or mixed with H$_2$O ice. We compared a high signal-to-noise spectrum of Miranda to synthetic and laboratory spectra of various candidate compounds to shed light on what species may be responsible for the 2.2-$\mu$m band. We conclude that the 2.2-$\mu$m absorption is best matched by a combination of NH$_3$ ice with NH$_3$-hydrates or NH$_3$-H$_2$O mixtures. NH$_4$-bearing salts like NH$_4$Cl are also promising candidates that warrant further investigation.Comment: 29 pages, 10 figures. Accepted for publication in Planetary Science Journa

Disagreement about Evidence-Based Policy

Evidence based-policy (EBP) is a popular research paradigm in the applied social sciences and within government agencies. Informally, EBP represents an explicit commitment to applying scientific methods to public affairs, in contrast to ideologically-driven or merely intuitive “common-sense” approaches to public policy. More specifically, the EBP paradigm places great weight on the results of experimental research designs, especially randomised controlled trials (RCTs), and systematic literature reviews that place evidential weight on experimental results. One hope is that such research designs and approaches to analysing the scientific literature are sufficiently robust that they can settle what really ‘works’ in public policy. Can EBP succeed in displacing reliance on domain-specific expertise? On our account, this is seldom, if ever, the case. The key reason for this is that underlying this approach is generally an appeal to argument by induction, which always requires further assumptions to underwrite its validity, and if not induction, some other argument form that also requires assumptions that are very often not validated for the case at hand