Overreaching
Definition
The error of stating a conclusion that the underlying data does not support. Overreaching is the single most common reason experts are damaged on cross-examination, because the gap between data and conclusion is exactly what opposing counsel will locate and expose.
- Definition
- Stating a conclusion the underlying data does not support
- Consequence
- Most common reason experts are damaged on cross-examination
- Cause
- Gap between data and conclusion opposing counsel can expose
- Context
- Expert witness testimony
Common questions
How does overreaching differ from a legitimate strong conclusion?+
A strong conclusion is legitimate when the data and validated method actually support that degree of certainty; overreaching occurs when the expert's stated confidence exceeds what the data, method limitations, or known error rates can justify.
How can an expert guard against overreaching in a written report?+
Common safeguards include stating findings using the exact language the underlying validation study supports, listing limitations explicitly, and having a peer or supervisor review the report specifically for claims that go beyond the data before it is finalised.
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...
- 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...
- The Report as Anchor
- The principle that an expert's opinion on the stand must be consistent with, and bounded by, the expert report filed before trial....