Daubert vs. Frye: A State-by-State Guide to Expert Witness Admissibility

Expert admissibility can shape a case long before trial. An expert can look strong on paper and still be excluded if the court sees a break in the chain between the method, the data, and the opinion being offered. In federal court, and in jurisdictions that use similar reliability screening, judges often focus on whether the opinion has a solid factual foundation, whether the approach is reliable, and whether the expert applied it carefully to the facts in the record.

For attorneys, the first question is jurisdiction. Does the court follow Daubert, Frye, or a state-specific framework? The second question is the one that often decides real motions: what will the judge expect you to show about methodology, validation, fit, and how the expert got from inputs to conclusions in this case?

This guide explains the difference between Daubert and Frye, highlights common jurisdictional patterns, and flags the admissibility issues that are easiest to miss if you wait until the motion to exclude lands.

What Is the Difference Between Daubert and Frye?

Frye

Frye asks whether the underlying principle or method has gained general acceptance in the particular field where it belongs. That focus tends to favor established techniques and can make newer methods harder to admit until the relevant community accepts them for the specific use being offered.

In Frye practice, disputes often turn on whether the technique is still experimental or has matured into something demonstrably accepted. Separate evidence rules still matter too. Courts typically analyze qualification, relevance, and foundation alongside any Frye inquiry.

Daubert

Daubert asks a different question. It focuses on reliability and fit, not just acceptance. Courts commonly consider, when they are meaningful for the discipline, whether the method can be tested, whether it has been peer reviewed, whether there are known or potential error rates, whether standards control its operation, and whether it is generally accepted.

In federal court, that analysis is tied directly to Federal Rule of Evidence 702 as part of the judge’s gatekeeping role. Under the current text of Rule 702, the proponent must demonstrate by a preponderance of the evidence that the testimony satisfies the rule’s requirements, including an adequate factual basis and a reliable application to the facts of the case.

The Real Strategic Difference

Here is the practical takeaway that shows up in motion practice.

• Frye is usually more focused on scientific consensus, especially when the technique is described as novel.
• Daubert is more focused on judicial gatekeeping and the reliability of the reasoning process.

Under Daubert, even a familiar method can be excluded if the expert cannot show it was applied reliably to the case facts. Credentials alone do not fix a weak method, and they do not fix a weak application.

Why Expert Admissibility Standards Matter

Rule 702 remains the governing standard in federal court, and it continues to shape briefing, hearings, and motion practice.

In practical terms, courts are not only asking whether the witness is qualified. They are asking whether the opinion is supported and connected, meaning:

• The testimony is based on sufficient facts or data
• The testimony is the product of reliable principles and methods
• The expert reliably applied those principles and methods to the facts

A simple admissibility gut check is this: can the judge read the report and clearly follow how the expert moved from the underlying evidence to the conclusion, step by step, without having to fill in missing reasoning?

Where Experts Get Excluded in Practice

The themes below are not a formal legal test. They are recurring problem areas that show up when courts analyze sufficiency of basis, reliability, and application.

1. Tool or method mismatch: The expert uses a tool that may be legitimate in general, but the record does not show it is reliable for the task, conditions, or decision point at issue.
2. Unexplained assumptions: The opinion depends on assumptions that are not justified, not tested, or not tied to record evidence. When the assumption drives the outcome, the factual basis starts to wobble.
3. Analytical gaps: The expert describes data and then announces a conclusion. The missing middle is the problem. Courts are wary of opinions that leap from inputs to outcomes without explaining the reasoning.
4. Case-specific application failures: Even when the method is accepted, judges still look at how it was applied. If the execution is not documented clearly, or the steps are not reproducible, the opinion can fail the “reliably applied” requirement.

Daubert vs. Frye: Updated State-by-State Overview

If you need a quick jurisdiction check before you retain an expert or brief admissibility, a one-glance state list helps. The labels below are based on the “Admissibility of Expert Testimony in All 50 States” chart published by Matthiesen, Wickert & Lehrer, S.C. (MWL), and they are included here with attribution to MWL.

MWL uses categories like “Modified,” “Daubert-like,” and “Other” for jurisdictions that do not fit neatly into a pure Daubert or pure Frye box. Treat those labels as a prompt to confirm controlling authority in your specific forum.

All 50 States

• Alabama — Daubert
• Alaska — Daubert
• Arizona — Daubert
• Arkansas — Daubert
• California — Frye
• Colorado — Daubert
• Connecticut — Daubert
• Delaware — Daubert
• Florida — Daubert
• Georgia — Daubert
• Hawaii — Modified Approach
• Idaho — Modified Approach
• Illinois — Frye
• Indiana — Modified Approach / No Specific Test
• Iowa — Daubert or Frye
• Kansas — Daubert
• Kentucky — Daubert
• Louisiana — Daubert
• Maine — Other (similar to Daubert)
• Maryland — Daubert
• Massachusetts — Daubert-Lanagan
• Michigan — Daubert
• Minnesota — Frye-Mack Standard
• Mississippi — Daubert
• Missouri — Daubert
• Montana — Daubert
• Nebraska — Daubert/Schaferman Standard
• Nevada — Other
• New Hampshire — Daubert
• New Jersey — Frye
• New Mexico — Partially Daubert
• New York — Frye
• North Carolina — Daubert
• North Dakota — N.D. R. Evid. 702
• Ohio — Daubert
• Oklahoma — Daubert
• Oregon — Modified Daubert
• Pennsylvania — Frye
• Rhode Island — Daubert-like Standard
• South Carolina — Other (similar to Daubert)
• South Dakota — Similar to Daubert
• Tennessee — Court can consider Daubert factors.
• Texas — Daubert-Robinson Standard
• Utah — Frye-like Standard
• Vermont — Daubert
• Virginia — Other
• Washington — Frye
• West Virginia — Daubert/Wilt Standard
• Wisconsin — Daubert
• Wyoming — Daubert

District of Columbia (Listed Separately by MWL)

• District of Columbia — Daubert

Bottom-Line Practice Point

Do not reduce every state to a one-word label. “Daubert” and “Frye” are useful shortcuts, but they can mislead if they hide a local statute, a state-specific gloss, or a special rule for novel scientific evidence. That is often where briefing problems start.

If your state is listed as “Modified,” “Other,” “Daubert-like,” or similar, treat that as a signal to confirm the controlling cases and any novelty trigger before you lock your expert plan.

How Attorneys Should Prepare Experts by Jurisdiction

The suggestions below are practical guidance for building a record that matches what courts are evaluating under the governing admissibility standard in your forum. They are not a substitute for the controlling rule, statute, or case law.

In Daubert Jurisdictions

Focus on proof and transparency. Judges want to see the reasoning, not just the result. A strong record usually includes:

• What was tested and what was not
• What standards or controls were used
• What limitations exist, including error rates where they are known and meaningful, and when they apply
• How the expert applied the method to the case facts, step by step
• Why the method actually fits the question the court has to decide

In Frye Jurisdictions

Focus on general acceptance where required, especially for newer techniques. Be ready to show that the relevant scientific community recognizes the method as legitimate for the specific use at issue. Also, do not neglect the separate foundation and relevance requirements that operate alongside Frye in many courts.

In Hybrid Jurisdictions

Prepare to satisfy multiple layers. Depending on the forum and the testimony, you may need to address reliability, foundation, helpfulness, and general acceptance at the same time. A good approach is to assume you will be asked two questions: “Is this method sound?” and “Did this expert use it soundly here?”

Key Takeaway

The most important admissibility question is not whether a jurisdiction is casually labeled Daubert or Frye. It is how that jurisdiction evaluates methodology, acceptance, fit, and application in real motion practice.

Attorneys who identify the governing standard early, then build the record around method reliability and case-specific application, are in a much stronger position to defend admissibility and challenge weak opposing opinions.