CALIFORNIA EVIDENCE: CIVIL AND CRIMINAL
...Opinion & Scientific Evidence
......Expert Testimony: In General
.........Things Expert May Not Rely On
............Unsupported Factual Assumptions
12 Cards On This Topic:

Trial court acted within its discretion in excluding opinion testimony that P company would have become extraordinarily successful had USC completed the clinical testing to which parties had contracted.

Challenge to admitting expert testimony is a challenge to the reliability and foundation of the evidence, and whether the subject is admissible as expert testimony; must be raised at trial.

An expert's assumption of facts contrary to the proof destroys the opinion.

Expert medical opinion evidence that is based upon a guess, surmise or conjecture, rather than relevant, probative facts, cannot constitute substantial evidence.

Expert's testimony that SUV's fuel pump relay was a possible cause of vehicle power loss properly precluded where testimony was speculative.

Plaintiff's experts on damages properly excluded from testifying where their opinions were based on hypothetical conjecture.

Sargon applies to expert opinion evidence submitted in connection with a motion for class certification.

Because doctor's expert testimony diagnosing D's mental disorder was based principally on assumed and hypothesized facts, judgment finding D had disorder was not supported by substantial evidence.

Supreme Ct. determined the trial ct. ruled correctly, thus foreclosing, as law of the case, further action in the trial ct. on lost profit damages.

Trial court did not err in excluding D's expert evidence that, if there were no shooting of mother, her fetus would have died anyway because of fatal medical condition.

An expert opinion must not be based upon speculative or conjectural data.

Expert opinions must have evidentiary support and may not be based solely on conjecture.