J.B. McCloughan wrote on Dec 12
th, 2007 at 5:37am:
Sergeant,
I don't know where it is that you came up with your “opinion” on Daubert/evidentiary standards but I would like to see it, as it is nothing I have seen in either the form of a high court opinion or even training on the issue for that matter.
Psychological tests and diagnosis fall far short of zero percent error rates you mentioned but those opinions are still admitted.
Could you also please point me to the extensive field research on other forensic disciplines?
I am of the understanding that there are some that have little to no field research and are completely dependent on statistical inference.
From the syllabus of Daubert v. Merrell Dow Pharmaceuticals (92-102), 509 U.S. 579 (1993), on the Cornell University Law School web site:
Quote:Many considerations will bear on the inquiry, including whether the theory or technique in question can be (and has been) tested, whether it has been subjected to peer review and publication, its known or potential error rate, and the existence and maintenance of standards controlling its operation, and whether it has attracted widespread acceptance within a relevant scientific community. The inquiry is a flexible one, and its focus must be solely on principles and methodology, not on the conclusions that they generate.
From Justice Blackmun’s opinion:
Quote:
Ordinarily, a key question to be answered in determining whether a theory or technique is scientific knowledge that will assist the trier of fact will be whether it can be(and has been) tested. "Scientific methodology today is based on generating hypotheses and testing them to see if they can be falsified; indeed, this methodology is what distinguishes science from other fields of human inquiry." Green, at 645. See also C. Hempel, Philosophy of Natural Science 49 (1966) ("[T]he statements constituting a scientific explanation must be capable of empirical test"); K. Popper, Conjectures and Refutations: The Growth of Scientific Knowledge 37 (5th ed. 1989) ("[T]he criterion of the scientific status of a theory is its falsifiability, or refutability, or testability").
Another pertinent consideration is whether the theory or technique has been subjected to peer review and publication. Publication (which is but one element of peer review) is not a sine qua non of admissibility; it does not necessarily correlate with reliability, see S. Jasanoff, The Fifth Branch: Science Advisors as Policymakers 61-76 (1990), and in some instances well grounded but innovative theories will not have been published, see Horrobin, The Philosophical Basis of Peer Review and the Suppression of Innovation, 263 J. Am. Med. Assn. 1438 (1990). Some propositions, moreover, are too particular, too new, or of too limited interest to be published. But submission to the scrutiny of the scientific community is a component of "good science," in part because it increases the likelihood that substantive flaws in methodology will be detected. See J. Ziman, Reliable Knowledge: An Exploration of the Grounds for Belief in Science 130-133 (1978); Relman and Angell, How Good Is Peer Review?, 321 New Eng. J. Med. 827 (1989). The fact of publication (or lack thereof) in a peer reviewed journal thus will be a relevant, though not dispositive, consideration in assessing the scientific validity of a particular technique or methodology on which an opinion is premised.
Additionally, in the case of a particular scientific technique, the court ordinarily should consider the known or potential rate of error, see, e. g., United States v. Smith,869 F. 2d 348, 353-354 (CA7 1989) (surveying studies of the error rate of spectrographic voice identification technique), and the existence and maintenance of standards controlling the technique's operation. See United States v. Williams, 583 F. 2d 1194, 1198 (CA2 1978) (noting professional organization's standard governing spectrographic analysis), cert. denied, 439 U.S. 1117 (1979).
You are absolutely correct if you mean that the Federal Rules of Evidence have never codified any further specifications than are broadly defined in Daubert v. Merrill Dow. However, I believe I have read somewhere that, all other factors being equal, testimony regarding a test with a high known error rate has less chance of being admitted then testimony regarding a test with a low known error rate. I don’t recall where I read that.
I think it is clear the polygraph falls short as a valid scientific test. I agree with the conclusions of the National Academy of Sciences in that regard. In their 2003 research study, The Polygraph and Lie Detection, those conclusions were as follows:
Quote:Polygraph Accuracy
Almost a century of research in scientific psychology and physiology provides little basis for the expectation that a polygraph test could have extremely high accuracy. The physiological responses measured by the polygraph are not uniquely related to deception. That is, the responses measured by the polygraph do not all reflect a single underlying process: a variety of psychological and physiological processes, including some that can be consciously controlled, can affect polygraph measures and test results. Moreover, most polygraph testing procedures allow for uncontrolled variation in test administration (e.g., creation of the emotional climate, selecting questions) that can be expected to result in variations in accuracy and that limit the level of accuracy that can be consistently achieved.
Theoretical Basis
The theoretical rationale for the polygraph is quite weak, especially in terms of differential fear, arousal, or other emotional states that are triggered in response to relevant or comparison questions. We have not found any serious effort at construct validation of polygraph testing.
Research Progress
Research on the polygraph has not progressed over time in the manner of a typical scientific field. It has not accumulated knowledge or strengthened its scientific underpinnings in any significant manner. Polygraph research has proceeded in relative isolation from related fields of basic science and has benefited little from conceptual, theoretical, and technological advances in those fields that are relevant to the psychophysiological detection of deception.
Future Potential
The inherent ambiguity of the physiological measures used in the polygraph suggest that further investments in improving polygraph technique and interpretation will bring only modest improvements in accuracy.