Many legal matters require the assistance of witnesses with specific expertise. Personal injury cases require information from doctors, a real estate valuation matter might require information from an appraiser, and a complex divorce might benefit from the assistance of an accountant. These witnesses with specific expertise are called expert witnesses. They are ordinarily hired on behalf of the client to provide information about the legal matter. Paralegals are often assigned the task of locating and hiring specific experts.

The initial interview with an expert is essentially a job interview. The paralegal should be trying to make a determination about whether this expert is right for this case. Although the selection of the expert is predetermined in many cases, the paralegal should still be on alert for signs that another expert should be considered.

Subsequent discussions with an expert usually involve exploring the factual underpinning for the expert's opinion. When an expert offers the opinion that an apartment fire was the result of arson, it is critical to understand the facts that support that opinion. Experts often make assumptions about the facts to reach their opinions. These assumptions must be examined as well to determine if they are justified and are consistent with other known facts. Effective interviewing of expert witnesses demands attention to detail.