The Report as Anchor
Definition
The principle that an expert's opinion on the stand must be consistent with, and bounded by, the expert report filed before trial. The report cannot be silently expanded or contracted during testimony; any departure must be acknowledged openly.
- Governs
- Expert trial testimony
- Core rule
- Testimony bounded by the filed expert report
- Deviation handling
- Any departure must be disclosed openly
- Relevant context
- Cross-examination
Common questions
What happens if testimony departs from the filed report?+
Opposing counsel can impeach the expert on the inconsistency, and courts may limit or exclude opinions that go beyond what the report disclosed as the basis for testimony.
Does this rule apply the same way in every jurisdiction?+
The underlying disclosure principle is near universal in expert-evidence practice, but the specific procedural rules and remedies for a departure vary by jurisdiction and court.
Related terms
- Concession
- An acknowledgment by the expert witness that a particular proposition put by counsel is correct. A partial concession accepts part of a...
- Cross-Examination
- Questioning of a witness by the opposing party. For an expert, cross-examination probes qualifications, methodology, the basis of opinions, limitations, inconsistencies with...
- Daubert Gatekeeping
- The judicial function under Daubert v. Merrell Dow Pharmaceuticals (1993) and Federal Rules of Evidence Rule 702, requiring the trial judge to...
- Overreaching
- The error of stating a conclusion that the underlying data does not support. Overreaching is the single most common reason experts are...
- Scope Creep
- The unintended expansion of a penetration test beyond the agreed boundaries, either because testers follow a vulnerability chain into an out-of-scope system...