While driving her parents’ vehicle, Cindy Law (plaintiff) pulled in front of another car driven by James Harder who swerved violently in order to avoid a collision. As a result, Harder’s car overturned. Harder and his wife were not wearing seat belts at the time and were thrown from the car and suffered serious injuries. The Harders filed suit against Law and her parents. During the court of discovery, the Laws sought information from the Harders concerning their experience with and use of seat belts. The Harders objected to the request as being irrelevant. The trial court ruled that that the Harders had no duty to wear seat belts. The Laws filed an interlocutory appeal to contesting the trial court’s determination. The court of appeals held that evidence of the Harders’s non-use of seat belts was admissible in the civil trial. The Harders appealed. The Arizona Supreme Court granted certiorari to review.