Jury instructions in Michigan are outlined in Michigan’s Model Civil Jury Instructions, Rule 4.01. MICH. MODEL CIVIL JURY INSTR. 4.01 (1993). This rule applies to all witnesses, including experts. Id. The rule instructs the jury that it has the authority to determine what witnesses to believe and how much weight to afford each expert witness. Id. When determining what witness(es) to believe, the jury should analyze the “witness’s ability and opportunity to observe, his or her memory, manner while testifying, any interest, bias or prejudice, and the reasonableness of the testimony considered in light of all the evidence.” Id.; Hitchcock v. Davis, 49 N.W. 912 (Mich. 1891). Rule 4.10 notes that no additional instruction is needed for expert witnesses in addition to that provided by Rule 4.01 and the considerations for evaluating the credibility of a witness’s testimony apply to expert witnesses as well. Id.
