Josephine Chesson, et al. v. Montgomery Mutual Insurance Co., No. 97, September Term 2012, Opinion by Battaglia, J.
EVIDENCE - ADMISSIBILITY OF SCIENTIFIC EVIDENCE - GENERAL ACCEPTANCE TESTIn a Workers' Compensation case, Montgomery Mutual Insurance Company sought review of a decision by the Circuit Court for Howard County admitting testimony by Dr. Ritchie Shoemaker that exposure to mold caused neurocognitive and musculoskeletal symptoms based on a "differential diagnosis," which he referred to as a "Repetitive Exposure Protocol." The Repetitive Exposure Protocol involved removing patients from the contaminated area, treating them, then returning them to the subject building, where, Dr. Shoemaker testified, the symptoms would re-develop. The Court of Appeals held that Dr. Shoemaker's testimony was not admissible under Frye-Reed, reasoning that his methodology was flawed and not generally accepted because it failed to account for the levels of mold exposure. The Court, moreover, concluded that based on an examination of relevant scientific journal articles that the scientific community remained uncertain as to Dr. Shoemaker's techniques and conclusions.
Barbera, C.J.
Harrell
Battaglia
Greene
Adkins
McDonald
*Bell,
JJ.
Opinion by Battaglia, J.
* Bell, C.J., now retired, participated in the hearing and conference of this case while an active member of this Court; after being recalled pursuant to the Constitution, Article IV, Section 3A, he also participated in the decision and adoption of this opinion.
When an expert opinion is offered to support the existence of new or novel scientific theory or methodology, "the basis of that opinion must be shown to be generally accepted as reliable within the expert's particular scientific field." Reed v. State, 283 Md. 374, 381, 391 A.2d 364, 368 (1978), citing Frye v. United States, 293 F. 1013, 1014 (1923). The conundrum presented in the instant Petition for Certiorari1 involves the meaning of "general acceptance" in the context of what was offered as a "differential diagnosis"2 that exposure to mold in a water-damaged office building allegedly caused non-respiratory neurocognitive and musculoskeletal symptoms.3
The general acceptance test imposes a significant gate-keeping role on the judge to determine whether a scientific theory or methodology should be admitted for considerationby the jury. Blackwell v. Wyeth, 408 Md. 575, 591, 971 A.2d 235, 245 (2009). The test originated in United States v. Frye, 293 F. 1013 (D.C. Cir. 1923), and was adopted by this Court in Reed v. State, 283 Md. 374, 389, 391 A.2d 364, 372 (1978). Writing for the Court in Reed, Judge John C. Eldridge explained that a novel scientific technique may be admitted in evidence only after a judge determines that it is recognized as demonstrable, as opposed to unverified, by the relevant scientific community:
"Just when a scientific principle or discovery crosses the line between the experimental and demonstrable stages is difficult to define. Somewhere in this twilight zone the evidential force of the principle must be recognized, and while courts will go a long way in admitting expert testimony deduced from a well-recognized scientific principle or discovery, the thing from which the deduction is made must be sufficiently established to have gained general acceptance in the particular field in which it belongs."
That is to say, before a scientific opinion will be received as evidence at trial, the basis of that opinion must be shown to be generally accepted as reliable within the expert's particular scientific field. Thus, according to the Frye standard, if a new scientific technique's validity is in controversy in the relevant scientific community, or if it is generally regarded as an experimental technique, then expert testimony based upon its validity cannot be admitted into evidence.
Id. at 381, 391 A.2d at 368, quoting Frye, 293 F. at 1014 (emphasis in original).
Determining whether a novel scientific theory is generally accepted in the relevant scientific community places the judge within the intersection of law and science. Unlike a trial, which involves a "quick and determinative" assessment of the evidence presented to determine whether guilt or liability is proven, the scientific inquiry "represents an ongoingcycle, in which each inquiry into an observable phenomenon is but one aspect of an ongoing quest" for knowledge. Blackwell, 408 Md. at 581, 971 A.2d at 239.
Driving this quest for knowledge is the scientific method, "the analytical process by which a hypothesis is tested and analyzed and conclusions or theories are developed." Id. at 581, 971 A.2d at 239. Theories are developed and tested, to be disconfirmed or subjected to further scrutiny through critique and continued study. A theory's validity and reliability are measured by its ability to be replicated, so that "general acceptance" relates to that which survives scientific scrutiny:
At the heart of this search for knowledge is the use of scientific method—or the analytical process by which a hypothesis is tested and analyzed and conclusions or theories are developed. This process has also been described as empirical study, that being study, "[f]ounded on practical experience, rather than on reasoning alone, but not established scientifically . . . [or] testing a hypothesis by careful observation, hence rationally based on experience." Stedman's Medical Dictionary 632 (28th ed. 2006) ("empiric"). In basic terms, the development of a theory, using the scientific method or empirical testing, follows characteristic steps:
1. Observations of some phenomenon are made.
. . .
2. Possible explanations (theories) are proposed for what is observed. . . .
3. Hypotheses are logically derived from the theories . . . .
4. Studies are designed to test the hypotheses. In essence, the study makes new observations that might disconfirm the hypothesis and thereby falsify the theory. Different theories have different implications and lead to different hypotheses. (Ideally, a study can be devised whose outcome will disconfirm one theory's hypotheses and not the other's. This is called a "critical experiment" because it permits a head-to-head test of two or more theories, and helps to determine which has done the best job of accounting for the relevant phenomena. Sometimes scientific controversies persist for a very long time because no commonly agreed upon critical experiment can be conducted.)
5. The results of such empirical tests lead to revision or abandonment of older theories or creation of still newer and hopefully better theories.
6. The process repeats itself as more empirical tests are conducted and theories undergo continued re-evaluation.
David L. Faigman, Michael J. Saks, Joseph Sanders & Edward K. Cheng, 1 Modern Scientific Evidence: The Law and Science of Expert Testimony, at 263-64 (2008[-2009]). Specifically, once a theory is conceived based on an observable phenomenon, a hypothesis, which is "[a] conjecture advanced for heuristic purposes, cast in a form that is amenable to confirmation or refutation by conducting of definable experiments and the critical assembly of empiric data," Stedman's [Medical Dictionary] 938 [(28th ed. 2006)], is developed, which defines the scope of an experiment. Studies then are designed to test the hypothesis and gather data:
To real scientists a finding of fact is only as good as the methods used to find it. Scientific method is the logic by which the observations are made. Well designed methods permit observations that lead to valid, useful, informative answers to the questions that had been framed by the researcher. For scientists, the key word in the phrase "scientific method" is method. Methodology—the logic of research design, measures, and procedures—is the engine that generates knowledge that is scientific. While for lawyers and judges credibility is the key to figuring out which witnesses are speaking truth and which are not, for scientists the way to figure out which one of several contradictory studies is most likely correct is to scrutinize the methodology.
Faigman, supra, at 260 (emphasis in original). Once data is compiled, analysis occurs, from which conclusions are drawn; the hypothesis either remains viable or is disproven:
Note that a hypothesis or a theory is never proven or confirmed to be true. Testing is capable only of disconfirming. But theories that withstand such attempts at falsification better and longer become accepted, at least until something better comes along. The opposite approach can readily be seen in non-scientific activities of numerous kinds, where investigators engage in a search for evidence that confirms their suspicions. This "confirmatory bias" is based on the erroneous assumption that a theory is confirmed by the accumulation of facts consistent with the theory . . . . It is the diligent search for inconsistencies, for falsification, that really puts a theory to the test. A theory that can withstand such scrutiny is one that deserves credence.
Id. at 264.
Blackwell, 408 Md. at 581-83, 971 A.2d at 240. Validity and reliability are the linchpins of the scientific method: validity, having been defined as "the extent to which something measures what it purports to measure," and reliability, characterized as "the ability of a measure to produce the same result each time it is applied to the same thing . . . consistency or reproducibility." Id. at 584, 971 A.2d at 240-41, quoting Faigman, supra, at 269.
In a courtroom, a judge or jury, obviously, is not able to replicate the scientific inquiryand explore whether a novel scientific theory is reliable and valid and thereby demonstrable. The general acceptance test, along with the other Frye-Reed prongs, ensures that the trier of fact focuses on the "rendition of a judgment on the...
