(a) Disclosure of Facts or Data.The expert may testify in terms of opinion or inference and give the expert’s reasons therefor without prior disclosure of the underlying facts or data, unless the court requires otherwise. The expert may in any event disclose on direct examination, or be required to disclose on cross-examination, the underlying facts or data.

(b) Voir dire. Prior to the expert giving the expert’s opinion or disclosing the underlying facts or data, a party against whom the opinion is offered upon request in a criminal case shall, or in a civil case may, be permitted to conduct a voir dire examination directed to the underlying facts or data upon which the opinion is based. This examination shall be conducted out of the hearing of the jury.

(c) Admissibility of opinion. If the court determines that the underlying facts or data do not provide a sufficient basis for the expert’s opinion under Rule 702 or 703, the opinion is inadmissible.

(d) Balancing test; limiting instructions. When the underlying facts or data would be inadmissible in evidence, the court shall exclude the underlying facts or data if the danger that they will be used for a purpose other than as explanation or support for the expert’s opinion outweighs their value as explanation or support or are unfairly prejudicial. If otherwise inadmissible facts or data are disclosed before the jury, a limiting instruction by the court shall be given upon request.

Notes and Comments
 Comment to 1997 change: Paragraphs (b), (c), and (d) are based on the former Criminal Rule and are made applicable to civil cases. This rule does not preclude a party in any case from conducting a voir dire examination into the qualifications of an expert.