Monday, September 03, 2012

Thinking about scientific knowledge

My friend Julianne pointed me to this interesting post on scientific knowledge on the Neuroskeptic blog. I rather like the discussion, but let me make some comments of my own.

That blog post emphasizes that science is based on an accumulated body of scientific knowledge, and that professional scientists are people who have shown mastery of that body of knowledge. I agree, but I note that the institutions of science have developed means to certify people who have completed their scientific training as scientists (the PhD and membership in professional societies). Professional scientists have also developed an understanding of the body of taxonomy underlying their field of research (for some this is relatively simple, but for scientists working in systematic biology, this is a major undertaking). I would add that graduate students, laboratory assistants and others working in scientific teams will be working under the guidance of professional scientists.

The blog post also emphasizes that controlled observation by scientists is fundamental to science. I agree, but I would add that professional scientists have learned the techniques of scientific observation from their field of science and have mastered the instruments used in observation.

Neuroskeptic downgrades the idea of "scientific method". I would point to the common process of drawing a hypothesis from theory and then making observations that can demonstrate that the hypothesis is false. Of course there are other scientific methods. Some of my old friends were "hay balers" who went out into the jungle to collect specimens of plants, always hoping to find something they did not recognize, and then classifying the plants that they found according to the evolving taxonomy. The work of these systematic biologists also follows a scientific method.

I also think science is done in communities. Of course there are geniuses like Newton, Mendel and Carnot who working in isolation managed huge advances in science. I suspect that we would not recognize them as scientists had they not communicated their findings to the scientific community, and had that community not vetted their work and found it useful. While scientist increasingly work in collaborative teams, I would also emphasize that it is in the replication of scientific observations that science differs from non-scientific observation.

Ask a scientist what kind of science he does and chances are he will identify with a community of scientists who write for each other and read each other's writings. The training of young people aspiring to be scientists is also a communal activity. I suggest that the organization of the body of theory and practice and definition of preferred ways of describing that knowledge also emerges from a community. Think of physicists using the same symbols and forms of equations, or chemists using common nomenclature for compounds.

I would not disparage scientific institutions -- professional societies and their journals, funding agencies and the peer review panels, universities and their curricula. We not only identify scientists by their participation in such institutions, but they could not do science without that participation.

Neuroskeptic's view
I rather like Neuroskeptic's argument that scientific knowledge and non-scientific knowledge should not be regarded as so different each from the other, but rather as different "colors" of knowledge. As is shown in the figure above, he sees different sciences as producing different kinds of knowledge. He seems not to see economics as a science, and presumably he sees literature as producing knowledge that is more different than scientific knowledge than does history or economics.

I would note that the Anglo-American classification of sciences differs from that of other societies. For example, UNESCO follows what I am told is the French practice in its "Social and Human Science" program, which includes both philosophy and history as well as what we would consider the social sciences.

I personally am opposed to any classification of forms of knowledge that defines that from anthropology, sociology, economics, geography and psychology as other than scientific. The social sciences involve observation by professionally trained and certified members of their profession, following from a body of theory that the members have mastered, vetted by peers, and shared within the institutions of their community. Still, the dotted line oval in the lower box is useful.

I do recognize that writers convey knowledge to readers through literature, and indeed that literature is a superior mode for conveying some kinds of knowledge than science.

Network of 1300 journal titles accessed by the users of the MyLibrary Web Service at the Los Alamos National Laboratory. The links shown denote a strong measure of co-occurrence (proximity) of two journals (the nodes) in user personalities. From this network, two main clusters were identified via Singular Value Decomposition: one pertaining to journals in chemistry, materials science, physics and the other to computer science and applied mathematics. A smaller cluster pertaining to journals in bioinformatics and computational biology is also highlighted. Figure better described in a recent paper describing our network approach to recommendation systems. Source
Modern clustering methods have been applied to journals, journal articles and other materials which reflect a structure somewhat like that used in Neuroskeptic's figure. Alternatively, one could try to actually define some dimensions for the description of forms of knowledge -- the power of the theory to predict new observations, the range of predictions, the degree of confidence in the theory, etc.

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