to interpret images or data and identify and group them according to particular professional training, rather than to simply depict them mechanically. Since the latter half of the nineteenth century, objectivity has come to involve a combination of trained judgment and mechanical objectivity. Objectivity in measurement Another methodological aspect is the avoidance of bias, which can involve cognitive bias, cultural bias, or sampling bias. Methods for avoiding or overcoming such biases include random sampling and double-blind trials. However, objectivity in measurement can be unobtainable in certain circumstances. Even the most quantitative social sciences such as economics employ measures that are constructs (conventions, to employ the term coined by Pierre Duhem). The role of the scientific community Next to unintentional and systematic error, there is always the possibility of deliberate misrepresentation of scientific results, whether for gain, fame, or ideological motives. Critiques of scientific objectivity A critical argument on scientific objectivity and positivism is that all science has a degree of interpretivism. In the 1920s, Percy Bridgman's The Logic of Modern Physics and the operationalism presented was centered in such recognition. Thomas Kuhn's The Structure of Scientific Revolutions Based on a historical review of the development of certain scientific theories in his book, The Structure of Scientific Revolutions, scientist and historian Thomas Kuhn raised some philosophical objections to claims of the possibility of scientific understanding being truly objective. In Kuhn's analysis, scientists in different disciplines organise themselves into paradigms within which scientific research is done, junior scientists are educated, and scientific problems are determined. When observational data arises which appears to contradict or falsify a given scientific paradigm, scientists within that paradigm historically have not immediately rejected it, as Karl Popper's philosophical theory of falsificationism would have them do. Instead they have gone to considerable lengths to resolve the apparent conflict without rejecting the paradigm. Through ad hoc variations to the theory and sympathetic interpretation of the data, supporting scientists will resolve the apparent conundrum. In extreme cases, they may ignore the data altogether. Thus, the failure of a scientific paradigm will go into crisis when a significant portion of scientists working in the field lose confidence in it. The corollary of this observation is that a paradigm is contingent on the social order amongst scientists at the time it gains ascendancy. Kuhn's theory has been criticised by scientists such as Richard Dawkins and Alan Sokal as presenting a relativist view