Opinions and Expert Testimony Flashcards
When may a lay witness offer an opinion, rather than a fact?
- A non-expert may offer opinion testimony if it is:
o “rationally based on the perception of the witness,” meaning based on the witness’s personal knowledge; and
o “helpful to a clear understanding or determination of a fact in issue.”
What is the proper scope of lay witness opinion?
- V: Value of one’s own property.
- E: Emotional state of others (happy/sad).
- M: Measurements - speed of a vehicle; height, weight, distance.
- P: Physical states - tall/short; healthy/sick.
- S: Sensory descriptions (smell, sound, taste, color).
May a lay witness offer a legal conclusion?
- Legal conclusions must be avoided and are inadmissible.
o EXAMPLE: The plaintiff was contributorily negligent.
o EXAMPLE: A contract existed.
o EXAMPLE: The defendant assaulted the victim.
What four factors must be considered to analyze an expert opinion?
- S = Proper Subject matter
- P = Proper Person (Qualified)
- O = Proper Opinion (Basis of the opinion)
- T = Proper Testimony (Offered in proper form)
What is required for the subject matter of an expert opinion to be proper?
- The subject matter of the opinion must require “scientific, technical, or other specialized knowledge” that “will help the trier of fact to understand the evidence or to determine a fact in issue”
What does it mean for an expert to be qualified?
- The expert must be qualified, meaning have specialized knowledge, skill, experience, training, or education specific to the subject matter
What must an expert opinion be based upon?
- The opinion must be based in sufficient facts or data
How certain must the expert opinion be?
- The testimony about the opinion must be expressed to “a reasonable degree of certainty.”
How does a court determine the reliability of an expert’s testimony?
- The Daubert elements (“TAPES”):
o T: Has the theory been tested? If so, how extensive?
o A: General acceptance in the relevant community.
o P: Peer review regarding the scientific theory.
o E: Degree or rate of error.
o S: Standards.
What is the minority rule for testing the reliability of an expert’s testimony?
- The Frye test is the minority rule. It has no elements, but rather, it only requires general acceptance of the test in the scientific community.
What are the three bases for an expert opinion’s testimony?
- (1) Personal knowledge (e.g., expert conducted exams or tests personally).
- (2) Facts presented to the expert at trial - expert sat in court and listened to witness testimony or is asked hypothetical questions.
- (3) Facts presented to the expert outside of court (reports, conversations - oftentimes this means the expert has consulted or relied on otherwise inadmissible evidence).
What is a limitation to an expert opinion based on facts presented outside of court?
- Reasonable Reliance Rule: These out-of-court facts must be of the type “reasonably relied upon” by other experts in the particular field.
- EXAMPLE: A doctor may rely on information from a nurse; an arson expert might rely on conversations with other people, including firefighters, as the basis for their testimony. This would typically be hearsay.
What is the test for admitting underlying data (Rule 703)?
- Underlying data that is otherwise inadmissible (typically hearsay) at trial CANNOT be revealed UNLESS the proponent shows the probative value of the evidence substantially outweighs its prejudicial effect.
How is the balancing test for underlying data under Rule 703 different from the Rule 403 balancing test?
- Rule 703 favors EXCLUSION of the underlying facts UNLIKE Rule 403, which favors inclusion.
Are experts allowed to give opinions that embrace an ultimate issue?
- Generally, an expert may give an opinion or inference which embraces an ultimate issue but cannot state the opinion as a legal conclusion.
