by Warranting causal claims — vouchers and clinchers Methods for warranting causal claims fall into two broad categories. There are those that clinch the conclusion but are narrow in their range of application; and those that merely vouch for the conclusion but are broad in their range of application. Derivation from theory falls into the first category, as do randomized clinical trials (RCTs), econometric methods and others. What is characteristic of methods in this category is that they are deductive: if they are correctly applied, then if the evidence claims are true, so too will the conclusions be true. That is a huge benefit. But there is an equally huge cost. These methods are concomitantly narrow in scope. The assumptions necessary for their
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Lars Pålsson Syll considers the following as important: Theory of Science & Methodology
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Warranting causal claims — vouchers and clinchers
Methods for warranting causal claims fall into two broad categories. There are those that clinch the conclusion but are narrow in their range of application; and those that merely vouch for the conclusion but are broad in their range of application.
Derivation from theory falls into the first category, as do randomized clinical trials (RCTs), econometric methods and others. What is characteristic of methods in this category is that they are deductive: if they are correctly applied, then if the evidence claims are true, so too will the conclusions be true. That is a huge benefit. But there is an equally huge cost. These methods are concomitantly narrow in scope. The assumptions necessary for their successful application tend to be extremely restrictive and they can only take a very specialized type of evidence as input and special forms of conclusion as output.
Those in the second category … are more wide ranging but it cannot be proved that the conclusion is assured by the evidence, either because the method cannot be laid out in a way that lends itself to such a proof or because, by the lights of the method itself, the evidence is symptomatic of the conclusion but not sufficient for it. What then is it to vouch for? That is hard to say since the relation between evidence and conclusion in these cases is not deductive and I do not think there are any good logics’ of non-deductive confirmation, especially ones that make sense for the great variety of methods we use to provide warrant …
My worry is that we want to use clinchers so that we can get a result from a small body of evidence rather than tackling the problems of how to handle a large amorphous body of evidence loosely connected with the hypothesis. This would be okay if only it were not for the down-side of these deductive methods – the conditions under which they can give conclusions at all are very strict.