What scientists know

Sat 30 Jun 2012 12:10 PM

I put a draft of my paper, What scientists know is not a function of what scientists know, on my website and on the PhilSci archive a couple of weeks ago. I'll be presenting it at the PSA in November.

ABSTRACT: There are two senses of 'what scientists know': An individual sense in which scientists report their own opinions, and a collective sense in which one reports the state of the discipline. The latter is what is of interest for the purpose of policy and planning. Yet an expert, although she can report the former directly (her opinion on some question), can only report her considered opinion of the latter (the community opinion on the question). Formal judgement aggregation functions offer more rigorous frameworks for assessing the community opinion. They take the individual judgements of experts as inputs and yield a collective judgement as an output. This paper argues that scientific opinion is not effectively captured by a function of this kind. In order to yield consistent results, the function must take into account the inferential relationships between different judgements. Yet the inferential relationships are themselves matters to be judged by experts involving risks which must be weighed, and the significance of the risk depends on value judgements.