The court permitted Blankenhorn to testify but reserved
the question of the appropriate weight to give to Blankenhorn’s
opinions. Tr 2741:24-2742:3. The court now determines that
Blankenhorn’s testimony constitutes inadmissible opinion testimony
that should be given essentially no weight.
Federal Rule of Evidence 702 provides that a witness may
be qualified as an expert “by knowledge, skill, experience,
training, or education.” The testimony may only be admitted if it
“is based upon sufficient facts or data” and “is the product of
reliable principles and methods.” Id. Expert testimony must be
both relevant and reliable, with a “basis in the knowledge and
experience of [the relevant] discipline.” Kumho Tire Co v
Carmichael, 526 US 137, 147, 149 (1999) (citing Daubert v Merrell
Dow Pharm, 509 US 579, 589, 592 (1993)).
While proponents correctly assert that formal training in
the relevant disciplines and peer-reviewed publications are not
dispositive of expertise, education is nevertheless important to
ensure that “an expert, whether basing testimony upon professional
studies or personal experience, employs in the courtroom the same
level of intellectual rigor that characterizes the practice of an
expert in the relevant field.” Kumho Tire, 526 US at 152. Formal
training shows that a proposed expert adheres to the intellectual
rigor that characterizes the field, while peer-reviewed
publications demonstrate an acceptance by the field that the work
of the proposed expert displays “at least the minimal criteria” of
intellectual rigor required in that field. Daubert v Merrell Dow
Pharm, 43 F3d 1311, 1318 (9th Cir 1995) (on remand) (“Daubert II”
.
The methodologies on which expert testimony may be based
are “not limited to what is generally accepted,” Daubert II at 1319
n11, but “nothing in either Daubert or the Federal Rules of
Evidence requires a district court to admit opinion evidence that
is connected to existing data only by the ipse dixit of the
expert.” General Electric Co v Joiner, 522 US 136, 146 (1997).
The party proffering the evidence “must explain the expert’s
methodology and demonstrate in some objectively verifiable way that
the expert has both chosen a reliable * * * method and followed it
faithfully.” Daubert II, 43 F3d at 1319 n11.
Several factors are relevant to an expert’s reliability:
(1) “whether [a method] can be (and has been) tested”; (2) “whether
the [method] has been subjected to peer review and publication”;
(3) “the known or potential rate of error”; (4) “the existence and
maintenance of standards controlling the [method’s] operation”; (5)
“a * * * degree of acceptance” of the method within “a relevant
* * * community,” Daubert, 509 US at 593-94; (6) whether the expert
is “proposing to testify about matters growing naturally and
directly out of research they have conducted independent of the
litigation,” Daubert II, 43 F3d at 1317; (7) whether the expert has
unjustifiably extrapolated from an accepted premise to an unfounded
conclusion, see Joiner, 522 US at 145-146; (8) whether the expert
has adequately accounted for obvious alternative explanations, see
generally Claar v Burlington Northern RR Co, 29 F3d 499 (9th Cir
1994); (9) whether the expert “employs in the courtroom the same
level of intellectual rigor that characterizes the practice of an
expert in the relevant field,” Kumho Tire, 526 US at 152; and (10)
whether the field of expertise claimed by the expert is known to
reach reliable results for the type of opinion the expert would
give, see id at 151.
