LAY WITNESS

any witness not testifying as an expert witness and who is thereby generally precluded from testifying in the form of an opinion. However, under federal rules a "lay witness" is able to testify in the form of an opinion or inference if the testimony is (a) rationally based on the perceptions of the witness, and (b) helpful to a clear understanding of his or her testimony or the determination of a fact in issue. The witness may be a LAY EXPERT WITNESS, meaning a person whose expertise or special competence derives from experience in a field of endeavor rather than from studies or diplomas. Source: Barron's Dictionary of Legal Terms, Steven H. Gifis, 5th Edition; © 2016