What actually changed

On December 1, 2023, an amendment to Federal Rule of Evidence 702 took effect. It was the most substantial revision to the rule governing expert testimony in roughly a quarter century, and courts and commentators are still working through what it means in practice.

For attorneys handling boundary, easement, and title matters, the amendment is worth understanding for a specific reason. Surveying testimony has historically been treated as comparatively safe from admissibility challenges. It is technical, it is grounded in a recognized professional discipline, and it rarely looks like the kind of novel science that draws a motion. The amendment’s emphasis on how reliably an expert applied their methodology to the particular facts makes that comfort less automatic.

The amendment clarified two things.

First, the party offering the expert bears the burden of establishing admissibility by a preponderance of the evidence. The rule now states that the court must find it more likely than not that each requirement is satisfied. The Advisory Committee’s stated concern was that many courts had been treating reliability as a question of weight for the jury rather than a threshold question of admissibility, and had effectively presumed expert testimony admissible.

Second, the rule was reworded to focus on whether the expert’s opinion reflects a reliable application of principles and methods to the facts of the case. The earlier formulation asked whether the expert had reliably applied the methodology. The revised language directs attention to the opinion itself.

There is genuine disagreement about how much these changes alter the practical standard. Some commentators describe them as clarifying rather than substantive. Others read them as a meaningful tightening of the gatekeeping function. Courts have cited the amended rule in excluding testimony, though the extent to which the new language is doing independent work remains unsettled.

Two practical points hold regardless of where that debate lands. The burden is explicitly yours. And the inquiry is focused on this opinion in this case, not on whether the expert’s general methodology is respectable.

Note that Rule 702 governs federal court. State standards vary considerably — some states track the federal rule closely, others follow different frameworks entirely. Check the standard in your forum.

Why this matters for surveying testimony

Surveying rarely presents the classic reliability problem. The methods are established, the professional standards are published, and the discipline is licensed. A surveyor’s general methodology is not usually what gets attacked.

The application is.

A boundary opinion is not a measurement. It is a conclusion about which evidence controls, reached by applying an established evidentiary hierarchy to a specific set of deeds, plats, monuments, and physical conditions. Two competent surveyors can measure identically and reach opposite conclusions because they weighed the evidence differently.

That is precisely the kind of reasoning the amended rule directs courts to examine. Not “is retracement a valid methodology” — it plainly is — but “did this expert reliably apply it to these facts.”

The four requirements, applied to a boundary opinion

The rule’s four requirements translate to boundary work fairly directly.

Will the testimony help the trier of fact? Usually yes. Where this becomes a problem is when the opinion is really a legal conclusion in technical clothing. An expert can explain why a monument controls over a distance. Whether a particular legal doctrine applies is generally for the court.

Is the testimony based on sufficient facts or data? This is a frequent weak point. An opinion built on a current-condition survey without retracing the original, or without examining the chain of title, or without visiting the site, is vulnerable. The question is whether the expert gathered enough to support the conclusion they reached.

Is it the product of reliable principles and methods? Generally the easiest requirement in surveying, because the principles are established and documented in recognized authority.

Does the opinion reflect a reliable application of those principles to these facts? The heart of it. Did the expert actually apply the order of conflicting elements, or state a conclusion and cite the hierarchy afterward? Is each step of the reasoning traceable? Does the report explain why particular evidence was credited and other evidence rejected?

Where survey expert testimony gets attacked

In practice, challenges cluster in a few places.

The expert measured but did not retrace. Locating existing monuments and describing current conditions is not the same as retracing the original survey. An opinion about where the boundary is, based only on where things currently are, has a gap in it.

The methodology was stated but not shown. A report that cites the hierarchy of evidence without demonstrating how it was applied to the specific conflicts in this case invites the argument that the conclusion came first.

Contrary evidence was not addressed. If the record contains a monument, a call, or an occupation pattern that cuts against the conclusion and the report does not engage with it, that omission is the cross-examination.

The opinion crossed into legal conclusion. Testifying that adverse possession has been established, rather than describing the physical evidence of occupation and its duration, is a predictable target.

Qualifications did not match the specific question. A licensed surveyor with extensive construction staking experience may not be the right witness on nineteenth-century metes and bounds retracement. The rule asks about qualification for this testimony.

What to ask before you retain

Given that the burden sits with you, a few questions are worth asking any survey expert before engagement.

Have you been challenged on admissibility, and what was the outcome? A candid answer is more informative than a perfect record.

How do you document the application of the evidentiary hierarchy in a report? You are listening for a real process, not a promise.

What would you need to reach a defensible opinion in this matter? An expert who tells you the file is insufficient before being retained is more valuable than one who does not.

How do you handle evidence that cuts against your conclusion? The answer should involve addressing it in the report, not omitting it.

Are you willing to tell me my theory is not supported? An expert whose conclusions always favor the retaining party has a pattern that opposing counsel can develop, and that pattern is itself an admissibility issue.

That last question matters more than it appears. An expert who will not say no is not a stronger witness. They are a more excludable one.

The practical takeaway

The amended rule did not change what makes surveying testimony reliable. It changed how explicitly you may need to demonstrate it, and it removed any presumption that technical testimony gets in because it is technical.

For boundary and title litigation, that puts the weight on the report. A report that shows its reasoning, engages the contrary evidence, and stays on the technical side of the line between opinion and legal conclusion is what survives a motion.

That is a matter of how the expert works, and it is worth evaluating before the engagement rather than after the motion.

Frequently asked questions

Did the 2023 Rule 702 amendment change the Daubert standard?

The amendment clarified Rule 702 rather than replacing the Daubert framework. It made explicit that the proponent bears the burden by a preponderance of the evidence and refocused the inquiry on whether the opinion reflects a reliable application of methods to the facts. Commentators disagree on how much this changes outcomes in practice.

Is surveying testimony subject to Rule 702 challenges?

Yes. Surveying is generally treated as technical rather than novel scientific evidence, which historically made challenges less common, but the rule applies. Challenges typically target the sufficiency of the data and the application of methodology to the specific facts rather than the validity of surveying methods generally.

What is the most common weakness in a survey expert report?

Measuring current conditions without retracing the original survey, and stating a conclusion without demonstrating how the evidentiary hierarchy was applied to the specific conflicts in the record.

Does Rule 702 apply in state court?

Rule 702 governs federal court. States vary — some have adopted analogous standards, others apply different frameworks. Confirm the standard in your forum.

Dr. Charles A. “Tony” Nettleman, III, PSM, Esq. is a licensed Professional Surveyor and Mapper and a licensed attorney with more than 20 years of experience. He co-authored Clark on Surveying and Boundaries, Brown’s Boundary Control and Legal Principles, and Evidence and Procedures for Boundary Location. He provides expert witness and consulting services to attorneys nationwide in boundary, easement, title, and standard of care matters.

Evaluating an expert for a boundary or title matter? Request a conflict check.

This article is general information about evidentiary standards and is not legal advice. Admissibility standards vary by jurisdiction. No attorney-client relationship is created by reading it.