T H E
D E T A I L
Monday, November 4, 2002
Good morning via the "Detail,"
a weekly e-mail newsletter that greets latent print examiners around the globe
every Monday morning. The purpose of the Detail is to help keep you informed of
the current state of affairs in the latent print community, to provide an avenue
to circulate original fingerprint-related articles, and to announce important
events as they happen in our field.
Many philosophers of science support Popper's (1963) view that science can advance only through a string of what he called conjectures and refutations. In other words, scientists should propose laws and theories as conjectures and then actively work to disprove or refute those ideas. Popper suggests that the absence of contrary evidence, demonstrated through an active program of refutation, will provide the best support available. It may seem like a strange way of thinking about verification, but the absence of disproof is considered support. There is one major problem with the idea of conjecture and refutation. Popper seems to have proposed it as a recommendation for scientists, not as a description of what scientists do. From a philosophical perspective the idea is sound, but there are no indications that scientists actively practice programs to search for disconfirming evidence. (Note from the Detail: ...and no unexplainable dissimilarities. :)
Another aspect of the inability of scientists to be objective is found in theory-laden observation, a psychological notion (Hodson, 1986). Scientists, like all observers, hold a myriad of preconceptions and biases about the way the world operates. These notions, held in the subconscious, affect everyone's ability to make observations. It is impossible to collect and interpret facts without any bias. There have been countless cases in the history of science in which scientists have failed to include particular observations in their final analyses of phenomena. This occurs, not because of fraud or deceit, but because of the prior knowledge possessed by the individual. Certain facts either were not seen at all or were deemed unimportant based on the scientists's prior knowledge. In earlier discussions of induction, we postulated that two individuals reviewing the same data would not be expected to reach the same conclusions. Not only does individual creativity play a role, but the issue of personal theory-laden observation further complicates the situation.
This lesson has clear implications for science teaching. Teachers typically provide learning experiences for students without considering their prior knowledge. In the laboratory, for instance, students are asked to perform activities, make observations and then form conclusions. There is an expectation that the conclusions formed will be both self-evident and uniform. In other words, teachers anticipate that the data will lead all pupils to the same conclusion. This could only happen if each student had the same exact prior conceptions and made and evaluated observations using identical schemes. This does not happen in science nor does it occur in the science classroom.
Related to the issue of theory-based observations is the allegiance to the paradigm. Thomas Kuhn (1970), in his ground-breaking analysis of the history of science, shows that scientists work within a research tradition called a paradigm. This research tradition, shared by those working in a given discipline, provides clues to the questions worth investigating, dictates what evidence is admissible and prescribes the tests and techniques that are reasonable. Although the paradigm provides direction to the research it may also stifle or limit investigation. Anything that confines the research endeavor necessarily limits objectivity. While there is no conscious desire on the part of scientists to limit discussion, it is likely that some new ideas in science are rejected because of the paradigm issue. When research reports are submitted for publication they are reviewed by other members of the discipline. Ideas from outside the paradigm are liable to be eliminated from consideration as crackpot or poor science and thus do not appear in print. (Note from the Detail... what are some examples of paradigms in latent prints?)
Examples of scientific ideas that were originally rejected because they fell outside the accepted paradigm include the sun-centered solar system, warm-bloodedness in dinosaurs, the germ-theory of disease, and continental drift. When first proposed early in this century by Alfred Wegener, the idea of moving continents, for example, was vigorously rejected. Scientists were not ready to embrace a notion so contrary to the traditional teachings of their discipline. Continental drift was finally accepted in the 1960s with the proposal of a mechanism or theory to explain how continental plates move (Hallam, 1975 and Menard, 1986). This fundamental change in the earth sciences, called a revolution by Kuhn, might have occurred decades earlier had it not been for the strength of the paradigm.
It would be unwise to conclude a discussion of scientific paradigms on a negative note. Although the examples provided do show the contrary aspects associated with paradigm-fixity, Kuhn would argue that the blinders created by allegiance to the paradigm help keep scientists on track. His review of the history of science demonstrates that paradigms are responsible for far more successes in science than delays.
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