Final answer:
Under federal procedures, the pretrial work of an expert consultant is not subject to discovery, while the work of an expert witness can be discovered since they testify at trial.
Step-by-step explanation:
As a general rule, at least under federal procedures, pretrial work done by an expert consultant is not subject to discovery by the opposing party. This is because an expert consultant is often hired to aid in the preparation of a case and their insights, working papers, and findings are usually considered to be privileged communications. In contrast, the work of an expert witness, who is expected to testify at trial, can be subject to discovery due to their role in presenting evidence to the judge or jury.