Glossary: evidence, discovery and AI terms for physician experts
Short version: 19 terms, each defined for how it matters when a physician expert witness uses AI. Other pages on this site link here the first time a term appears.
Limits: We read every rule, ruling and product page on the date shown and did not test any product with patient records. Court summaries here are not legal advice; how your court treats AI use depends on the jurisdiction and the judge, so ask retaining counsel.
Admissibility terms
- Rule 702 (Federal Rule of Evidence 702)
- The federal rule on expert testimony. Since 2023-12-01 the party offering an expert must show it is more likely than not that the testimony helps the fact-finder, rests on sufficient facts or data, uses reliable methods and applies them reliably. Many states copy it in whole or part.
- Daubert
- Daubert v. Merrell Dow Pharmaceuticals (1993), the Supreme Court case that made trial judges gatekeepers of expert reliability. Also shorthand for the hearing or motion where the other side asks the judge to exclude an expert.
- Kumho Tire
- Kumho Tire v. Carmichael (1999), which applied Daubert gatekeeping to all expert testimony, including experience-based clinical opinions, and asks whether the expert used the same intellectual rigor as in practice.
- Frye
- The older test from Frye v. United States (1923): an expert's method must be generally accepted in the relevant field. New York still uses it, which is why Matter of Weber asked whether AI use was accepted among fiduciary experts.
- Ipse dixit
- Latin for "he himself said it." In General Electric v. Joiner (1997), an opinion linked to the data only by the expert's say-so. An AI-written conclusion you can't explain invites the same label.
- Rule 707 (proposed)
- A proposed evidence rule that would apply the Rule 702 test to machine output offered without an expert witness. Published for comment in August 2025; the advisory committee declined to advance it on 2026-05-07. Not in force.
- Motion in limine
- A pretrial request to keep evidence out. A Daubert challenge to an expert is often filed as one.
- Standard of care
- What a reasonably careful physician in the same field would have done in the same circumstances, judged by the standard in force when the care happened, not today's.
Discovery and disclosure terms
- Facts or data considered
- What Rule 26(a)(2)(B)(ii) requires an expert report to list. It covers material the expert considered, not only what the expert relied on. In Villanueva (2026), ChatGPT case summaries an expert consulted counted.
- Work product
- Material prepared in anticipation of litigation, protected from discovery in many cases. Rule 26(b)(4)(B) extends it to drafts of an expert's report in any form, and Rule 26(b)(4)(C) to most communications with retaining counsel.
- Rule 29 stipulation
- An agreement between the parties that changes discovery, often barring discovery of expert notes and drafts. CLF v. Shell (2026) held a generic one didn't cover AI prompts; to cover them, it must say so.
- Engagement letter
- The retention agreement between you and counsel. Law firms have begun adding AI terms: approved tools, approval steps, keeping prompts and outputs, and a duty to verify.
- Prompt log (chat history)
- The dated record a chatbot keeps of every prompt and answer. It is the document behind most AI questions at deposition, and parts of it have been ordered produced.
Records and AI terms
- BAA (business associate agreement)
- The HIPAA contract a vendor signs before it may handle protected health information on someone's behalf. No BAA covering the exact product and plan means no patient records in it.
- PHI (protected health information)
- Health information that identifies a person. A litigation record file is full of it, and a protective order in the case may add its own limits.
- Hallucination
- Output an AI model states as fact that is false or invented: a citation to a paper that doesn't exist, a date that isn't in the record. The Kohls declaration was excluded over invented citations.
- Page citation
- A reference from an AI output line to the page of the record it came from. It is what makes an AI chronology checkable, and checkable is what makes it defensible.
- Chronology
- A dated list of medical events drawn from the record. For an expert it is a finding aid; the opinion rests on the pages, not the list.
- Deduplication
- Removing repeat copies of the same page. Litigation files from several providers carry many; removing them cuts reading time and, with per-page billing, cost.