An expert witness reference
An expert witness reference

Expert Witness Reference

An expert witness is a person permitted to give opinion testimony because specialized knowledge will help the trier of fact — and whose opinion has to clear a reliability threshold before a jury ever hears it. This site explains that threshold, the motions that test it, and the engagement around it: 13 pages on the standards, 13 on the practice, and 9 guides. Published by Hartzer Consulting.

The expert behind it
Working in the field since
1996
Expert reports
36
Depositions
8
Trials
5
Arbitrations
1
What this covers

Two questions, and almost every expert problem is one of them


Either the opinion has to get in, or the other side's has to be kept out — and both run through the same rule. Federal courts apply FRE 702 as amended on 1 December 2023; a minority of state courts still apply some version of general acceptance. Which one governs decides what the expert has to show.

Whose move

Standards and Admissibility

13 pages on Rule 702, the Daubert factors, Frye and the state divergence, and the motions that decide it — each labelled with whether it is the proponent's burden, the opponent's move, or the court's call.

See the standards →

When

Retention and Practice

13 pages on the engagement — finding and vetting, fees and who pays for what, the report and the disclosure, the deposition and trial. Most of the expensive mistakes are made before anyone is retained.

See the practice →

Most read

The pages counsel opens first


Everything on this site →

Before the motion

Three things worth settling early


These are written to be useful to a reader who never makes contact. A conflict that surfaces after disclosure, a scope that was never defined, and a fee arrangement nobody wrote down are the three that cost the most and are the cheapest to avoid.

By group

The seven groupings everything sits in


The Federal Framework

5 pages

Rule 702, Daubert, and the decisions that built the gatekeeping obligation.

Daubert Daubert Factors FRE 702 FRE 703 Kumho and Joiner

Frye and the States

3 pages

Where the forum's standard is not the federal one, and how far it diverges.

Frye Daubert vs Frye By State

How It Is Raised

5 pages

The motions, the hearing, and the moment admissibility is actually decided.

Daubert Hearing Daubert Motion Daubert Challenge Motion in Limine Voir Dire

Finding and Vetting

4 pages

Before anyone is retained, and where the expensive mistakes are made.

Finding an Expert Vetting Directories Conflicts

Money and Terms

3 pages

What it costs, who pays for what, and what the engagement letter fixes.

Fees and Rates Who Pays Engagement Letters

The Record

3 pages

The report, the disclosure, and everything that becomes discoverable.

The Report Rule 26 Disclosure Drafts

Deposition and Trial

3 pages

After disclosure, when the record is fixed and what remains is examination.

Deposition Rebuttal Trial Testimony

Browse the practice areas →

Keep reading

Retaining an expert, or facing one

Hartzer Consulting is retained by counsel on both sides in matters involving internet technology, search, digital advertising and domain names. A conflict check comes first, so a first message should describe the parties in general terms only.

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