§ 25.07 Key Points

• Jurisdiction: North Carolina

§ 25.07 Key Points

To be relevant, an expert's opinion must be based on the facts in the particular case. Moreover, if the jury rejects those facts (they may be disputed), the jury should also reject the opinion.

Rule 703 recognizes three bases for expert testimony: (1) firsthand knowledge of the expert (e.g., treating physician), (2) assumed facts that are in the record, typically in the form of a hypothetical question, and (3) nonrecord facts if of a type reasonably relied upon by experts in the field.

Hypothetical Questions Based on Record Facts

Material facts. Some jurisdictions require that the hypothetical question contain all the "material" facts. Otherwise, there is a risk that the jury may be misled because the offering party—by omitting some facts—could elicit an opinion grounded on a faulty basis. Nevertheless, many courts reject this requirement. Instead, they deal with the issue by allowing the cross-examiner to change the hypothetical question by including additional facts. Moreover, the trial judge retains discretion under Rule 403 and may require the examiner to rephrase an unfair or misleading hypothetical question.

"Modified" hypothetical questions. An expert present during the testimony of other witnesses may base an opinion on that testimony. The expert is simply asked to assume that the overheard testimony is true. In general, this procedure is practicable only when the case is simple and the testimony concerning the underlying data is not disputed; otherwise the jury may not know upon what data the opinion is based.

Opinion Based on Nonrecord Facts: "Reasonable Reliance" Requirement

In addition to personal knowledge and hypothetical questions, Rule 703 permits an expert to give an opinion based on information supplied to the expert outside the record (nonrecord facts), if of a type reasonably relied upon by experts in the particular field. The drafters of the Federal Rules wanted to bring the courtroom use of expert testimony into conformity with how information is used in practice by experts.

Nevertheless, Rule 703 has its detractors. First, it assumes extensive pretrial...