Overview
The material on this site is grouped seven ways, and the grouping is not alphabetical or thematic. Each group collects the questions that arise at one point in a case, because that is when a reader has them. Three groups sit inside standards and admissibility; four sit inside retention and practice.
Federal — the framework itself
The federal group covers FRE 702 as amended effective 1 December 2023, the rule on the basis of an opinion, and the Supreme Court trilogy that produced the modern gatekeeping obligation. It answers what a proponent has to establish and what the court is deciding when it decides admissibility: a preliminary question under FRE 104(a), on which the proponent carries the burden by a preponderance.
This group is where the most frequently mis-stated propositions in the whole field live — that the reliability factors are a checklist, that gatekeeping applies only to scientific evidence, that the 2023 amendment created a new standard. Each of those is addressed with the language of the opinion or the committee note that contradicts it.
States — where the framework may not apply
The states group covers the general-acceptance test, its origin in a two-page 1923 decision, the comparison that is asked about more than anything else on this subject, and the actual state-by-state position. Its purpose is corrective. The country is not divided into two camps; a large majority of states apply something functionally like the federal rule, a small group still gates novel scientific methodology on general acceptance, and a substantial middle group has its own articulated standards belonging to neither label.
The group also carries the point that decides how useful any of this is in a given case: a correct statement about federal practice can be a wrong statement in the courthouse where the case is pending, and published charts of state standards go out of date faster than they are revised.
Motions — how the question is raised and decided
The motions group covers the vehicles: the motion in limine, the reliability motion and its briefing, the hearing that is sometimes held, and voir dire of the witness before an opinion is given. It answers procedural questions rather than substantive ones — when the objection must be made, what record the ruling is made on, whether a hearing is required at all, and what survives review.
The recurring theme is that the vehicle determines the record and the record determines the outcome on appeal, where these rulings are reviewed for abuse of discretion. A party that wins the argument and loses the record has usually lost.
Finding — before anyone is retained
The first practice group covers how experts are actually found, how a candidate is vetted, how the market of directories, brokers and subscription platforms works, and how a conflict check is run.
Its organizing insight is that the federal disclosure rule already specifies most of what a buyer should ask for, and that the channels through which experts are found are businesses with different people paying — which shapes what each of them can and cannot tell a buyer. Nothing in this group ranks or compares specific directories or referral services; the structures are described, the businesses are not.
Terms — money and paperwork
The second practice group covers fees, the fee-shifting rule for expert discovery, and the engagement letter. It explains what the published surveys measured and who ran them, how a quotation is structured, which terms decide the size of a bill, and who is contractually liable for it.
It also corrects the most expensive misconception in the category: that the other side pays for the expert. The federal rule shifts a reasonable fee only for time spent responding to expert discovery, which leaves review, analysis, the report and trial with the retaining party, and whether an expert’s deposition preparation time shifts at all is genuinely split among district courts.
Record — what gets created and produced
The third practice group covers the report, the disclosure rules that govern it, and the treatment of drafts and attorney–expert communications. The report is required to be a complete statement of the opinions with their basis and reasons, and the deposition is not a cure for an incomplete one.
The material here is written around one word — considered, the standard for what has to be disclosed, which reaches material read and rejected — and around the limits of the 2010 work-product protections, which are qualified, carry three express exceptions, and do not reach the expert’s own notes or communications with anyone other than retaining counsel.
Testimony — after the record is fixed
The fourth practice group covers the deposition, rebuttal reports and testimony at trial. By this stage the report has been served and the record is largely closed, and the questions become examination questions: what a deposition is actually for, what a rebuttal report may and may not contain, and what happens at trial to material the expert relied on that is not itself admissible.
These are the pages an attorney reaches for late in a case, and they are written on the assumption that the decisions which determine how these stages go were made months earlier and cannot now be revisited.
Why seven and not two
Two categories are enough for navigation and not enough for use. The questions that arise before retention have almost nothing in common with the questions that arise after disclosure, even though both concern the same witness. Grouping by stage means a reader arriving with a problem lands among the other problems that arise at the same moment, which is the most reliable predictor of what they will need next.
Published