Okla. Stat. tit. 12, § 12-2703: Bases of opinion testimony by experts

The facts or data in the particular case upon which an expert

bases an opinion or inference may be those perceived by or made

known to the expert at or before the hearing. If of a type

reasonably relied upon by experts in the particular field in forming

opinions or inferences upon the subject, the facts or data need not

be admissible in evidence in order for the opinion or inference to

be admitted. Facts or data that are otherwise inadmissible shall

not be disclosed to the jury by the proponent of the opinion or

inference unless the court determines that their probative value in

assisting the jury to evaluate the expert's opinion substantially

outweighs their prejudicial effect.