Eyewitness testimony

Research in eyewitness testimony is mostly considered a subfield within legal psychology, it is however a field with very broad implications. Normally are human reports based on visual perception believed to be very reliable (if not irrefutable). Research in cognitive psychology, in social psychology, as well as in the philosophy of science and in other fields seems, however, to indicate that the reliability of visual reports are often much overrated.

Epistemological aspects
A traditional view is that theories are tested against observations, so that we have a clear demarcation between theoretical and observational statements; the former confirmed or disconfirmed by the latter. This view is associated with positivism. The opposite view is that observations are theory-laden: It is in particular associated with Norwood Russell Hanson (1924-67), Thomas S. Kuhn (1922-1996), and Paul K. Feyerabend (1924-1994). The property of observations varying with or depending upon the theoretical commitments of the observer. Insofar as observations are theory laden, your beliefs - as shaped by the theory or paradigm you accept - determines what you observe, so that partisans of different theories (or paradigms) will observe differently. (See [Theory-ladenness]

Findings from History
Main entry: Historical method

R. J. Shafer offers this checklist for evaluating eyewitness testimony: (Garraghan, 1946, pp. 157-158).


 * 1) Is the real meaning of the statement different from its literal meaning?  Are words used in senses not employed today?  Is the statement meant to be ironic (i.e., mean other than it says)?
 * 2)  How well could the author observe the thing he reports?  Were his senses equal to the observation?  Was his physical location suitable to sight, hearing, touch?  Did he have the proper social ability to observe: did he understand the language, have other expertise required (e.g., law, military); was he not being intimidated by his wife or the secret police?
 * 3) How did the author report?, and what was his ability to do so?
 * 4) Regarding his ability to report, was he biased?  Did he have proper time for reporting?  Proper place for reporting?  Adequate recording instruments?
 * 5) When did he report in relation to his observation?  Soon?  Much later?
 * 6) What was the author's intention in reporting?  For whom did he report?  Would that audience be likely to require or suggest distortion to the author?
 * 7)  Are there additional clues to intended veracity?  Was he indifferent on the subject reported, thus probably not intending distortion?  Did he make statements damaging to himself, thus probably not seeking to distort?  Did he give incidental or casual information, almost certainly not intended to mislead?
 * 8)  Do his statements seem inherently improbable: e.g., contrary to human nature, or in conflict with what we know?
 * 9)  Remember that some types of information are easier to observe and report on than others.
 * 10)  Are there inner contradictions in the document?

Louis Gottschalk adds an additional consideration: "Even when the fact in question may not be well-known, certain kinds of statements are both incidental and probable to such a degree that error or falsehood seems unlikely. If an ancient inscription on a road tells us that a certain proconsul built that road while Augustus was princeps, it may be doubted without further corroboration that that proconsul really built the road, but would be harder to doubt that the road was built during the principate of Augusutus.  If an advertisement informs readers that 'A and B Coffee may be bought at any reliable grocer's at the unusual price of fifty cents a pound,' all the inferences of the advertisement may well be doubted without corroboration except that there is a brand of coffee on the market called 'A and B Coffee.'" (Gottschalk, 1950, p. 163).

Garraghan says that most information comes from "indirect witnesses," people who were not present on the scene but heard of the events from someone else (Garraghan, 1946, pp. 292). Gottschalk says that a historian may sometimes use hearsay evidence. He writes, "In cases where he uses secondary witnesses, however, he does not rely upon them fully. On the contrary, he asks: (1) On whose primary testimony does the secondary witness base his statements?  (2) Did the secondary witness accurately report the primary testimony as a whole?  (3) If not, in what details did he accurately report the primary testimony?  Satisfactory answers to the second and third questions may provide the historian with the whole or the gist of the primary testimony upon which the secondary witness may be his only means of knowledge.  In such cases the secondary source is the historian's 'original' source, in the sense of being the 'origin' of his knowledge.  Insofar as this 'original' source is an accurate report of primary testimony, he tests its credibility as he would that of the primary testimony itself." (Gottschalk, 1950, p. 165).