The admissibility of expert testimony is governed by Evid.R. 702, which provides as follows:
A witness may testify as an expert if all of the following apply:
(A) The witness’ testimony either relates to matters beyond the knowledge or experience possessed by lay persons[; ]
(B) The witness is qualified as an expert by specialized knowledge, skill, experience, training, or education regarding the subject matter of the testimony;
(C) The witness’ testimony is based on reliable scientific, technical, or other specialized information. To the extent that the testimony reports the result of a procedure, test, or experiment, the testimony is reliable only if all of the following apply:
(1) The theory upon which the procedure, test, or experiment is based is objectively verifiable or is validly derived from widely accepted knowledge, facts, or principles;
(2) The design of the procedure, test, or experiment reliably implements the theory;
(3) The particular procedure, test, or experiment was conducted in a way that will yield an accurate result. Evid.R. 702.
In order to determine reliability, a court must assess whether the reasoning or methodology underlying the testimony is valid. Miller v. Bike Athletic Co. (1998), 80 Ohio St.3d 607, 611. Thus, an expert may not base an opinion upon “subjective belief or unsupported speculation.” Daubert v. Merrell Dow Pharmaceuticals, Inc. (1993), 509 U.S. 579, 590. Instead, the expert’s opinion must be based on methods and procedures that meet the level of intellectual rigor demanded by the relevant discipline. See In re Paoli (C.A.3, 1994), 35 F.3d 717, 742, citing Daubert, 509 U.S. at 590. The “[p]roposed testimony must be supported by appropriate validation — i.e., ‘good grounds,’ based on what is known.” Daubert, 509 U.S. at 590. And “where such testimony’s factual basis, data, principles, methods, or their application are called sufficiently into question, * * * the trial judge must determine whether the testimony has a reliable basis in the knowledge and experience of [the relevant] discipline.” Daubert, 509 U.S. at 592.