Defense survey rebuttal expert

Expert class library · Consumer class actions · Defense side

Critiques plaintiff surveys for design flaws such as leading questions, missing controls, and unrepresentative samples. May run a competing survey to show the claim did not matter to buyers.

Questions this testimony turns on

• Is the rebuttal expert qualified to critique every part of the plaintiffs' survey, including the quantitative or econometric steps that turn survey answers into a price premium?
• Do the criticisms of the plaintiffs' survey, such as question wording, universe definition, or control design, go to admissibility or only to weight?
• Is a survey taken years after the relevant date still probative, and how should the delay affect the weight it receives?
• Does the defense competing survey test the same claims, purchasers, and marketplace conditions as the survey it rebuts?

Methods

• Survey design critique
• Control group testing
• Sample representativeness analysis
• Competing materiality survey

How the testimony is attacked

• Critique exceeds the expert's expertise. Plaintiffs argue a survey methodologist cannot attack the economic or quantitative output of a conjoint study. In Townsend v. Monster Beverage the court excluded the defense survey expert's two paragraphs calling the plaintiffs' conjoint price premium implausible because they rested on quantitative methods outside his expertise, while admitting his other survey design criticisms.
• No hands-on experience with the challenged method. Plaintiffs argue an expert who has never performed a conjoint analysis cannot opine on whether one is valid. In In re FCA US LLC the court excluded all of the defense economist's testimony on the propriety of the plaintiffs' conjoint analysis because he admitted he had no conjoint expertise, but allowed his own analysis of used vehicle prices.
• Survey design flaws in the rebuttal survey itself. Plaintiffs attack the defense survey on recall questions, cutoff dates, universe definition, marketplace realism, and test and control comparisons. Townsend held that such challenges to survey design and methodology go to weight, not admissibility.
• Survey taken long after the relevant date. Plaintiffs argue a defense survey is irrelevant because it was fielded years after the date that matters. In Bern Unlimited v. Burton the court refused to exclude the defendants' secondary meaning survey on that basis, holding that the delay goes to the strength of the evidence.
• Cumulative or derivative of another defense expert. Plaintiffs argue the survey rebuttal merely repeats the defense economist. Townsend rejected the argument because the two experts brought distinct expertise and objectives even where some criticisms overlapped.

What the public record shows

Courts have filed at least 85 opinions since 2015 that discuss this class of testimony and cite Daubert or Rule 702, as of October 2, 2026. Three that show how courts handle this class of testimony:

Each case links to the free opinion text on CourtListener.

In federal court: amended Rule 702

In federal court, since December 1, 2023, Rule 702 says expressly that the party offering an expert must show the court it is more likely than not that the testimony meets each requirement: that it rests on sufficient facts or data, uses reliable methods, and reflects a reliable application of those methods to the case. Questions about the basis of an opinion are no longer automatically matters of weight for the jury. For how the circuits have applied the amendment, see the Rule 702 tracker, which follows each court of appeals; for what that means for preparing or attacking this class of expert, see the guide on amended Rule 702.

Related classes

• Consumer perception survey expert
• Conjoint survey damages expert
• Trademark likelihood-of-confusion survey expert

Guides

• Amended Rule 702 After Nearly Three Years: What Courts Exclude

Simulating this class on a matter

Supreme Mind simulates a class of expert, never a named individual, on your fact pattern and returns the likely opinion, the ranked cross-examination weaknesses, the Rule 702 attack surface and what it means for settlement. Read how it works, or book a demo.

Updated October 2, 2026. How this page is built: rulings are found by searching court opinions on CourtListener. The summaries are written by AI working from the full text of each opinion, and every citation and link is checked automatically. Outcomes are labelled by what the court did with the expert’s testimony. No individual expert is named. This page summarises public decisions for orientation and is not legal advice; read the opinion before relying on any ruling. Spotted an error? Tell us.