Claim Construction: 6 Keys to Winning a Markman Hearing

Most patent cases are won or lost long before a jury hears the word infringement. They turn on a single pretrial ruling — claim construction — where the judge decides exactly what the words in your patent claims mean. Get a key term read your way and the other side often settles by morning. Lose it, and a patent you spent years and a fortune building can collapse in an afternoon. If you are heading toward litigation or an IPR, this is the fight that matters most.

What Is Claim Construction?

Claim construction is the process by which a court decides the meaning and scope of the terms in a patent’s claims. The claims are the legal boundary of the invention — the fence line of the property — so fixing what each disputed word means effectively decides how far that property extends.

The Supreme Court settled who does this job in Markman v. Westview Instruments, 517 U.S. 370 (1996): interpreting patent claims is a question of law for the judge, not the jury. The reasoning was practical. Judges bring interpretive expertise, and having courts rather than juries fix claim meaning promotes uniform, predictable results across cases and jurisdictions.

Because a term can read the accused product out of the claim (no infringement) or read prior art into it (invalidity), a single construction can end the case. That is why so much litigation energy pours into a handful of words.

The Markman Hearing: How It Works

The pretrial proceeding where the court hears argument on claim meaning is called a Markman hearing. The choreography is fairly consistent from court to court:

1. The parties identify the claim terms genuinely in dispute — usually a small set that actually drives infringement or validity.
2. Each side proposes a construction for those terms and supports it with evidence.
3. The parties exchange claim-construction briefs, often with a joint chart lining up the competing proposals.
4. The judge holds the hearing, where lawyers and sometimes technical experts argue the terms.
5. The court issues a claim-construction order fixing the meaning of each disputed term for the rest of the case.

Districts with local patent rules — the Eastern District of Texas, the Northern District of California, and others — formalize this with deadlines for exchanging proposed terms and a joint claim-construction statement. That statement is a side-by-side chart of each disputed term, every side’s proposed meaning, and the intrinsic and extrinsic support each cites. It becomes the roadmap the judge uses at the hearing.

Many judges also invite a technology tutorial before or during the hearing, where the parties teach the court the underlying science in neutral terms. Treat it as a real opportunity: a judge who understands how the invention works is far more likely to adopt a construction that fits the technology. Timing varies, but the hearing usually lands after enough discovery to frame the disputes and before expert discovery and summary judgment. In many districts it is the pivot point of the entire schedule.

How Judges Decide: The Phillips Hierarchy

The controlling framework comes from Phillips v. AWH Corp., 415 F.3d 1303 (Fed. Cir. 2005) (en banc). Phillips ranks the evidence a court may use and tells judges to start inside the patent before looking outside it.

1. Intrinsic evidence comes first: the claims themselves, then the specification — which Phillips called the single best guide to a disputed term’s meaning — and then the prosecution history.
2. Extrinsic evidence, such as dictionaries, treatises, and expert testimony, is secondary and cannot override a clear intrinsic meaning.
3. Terms are read as a person of ordinary skill in the art would have understood them at the time of the invention, not with hindsight.

The practical lesson: your best arguments are already sitting in your own patent. A construction anchored in the specification and prosecution history almost always beats one propped up by a dictionary.

Why Claim Construction Usually Decides the Case

Once the order issues, the range of outcomes narrows sharply. If the court construes a term narrowly, the accused product may fall outside the claim and infringement evaporates. If it construes a term broadly, the claim may now cover the prior art and become vulnerable to invalidity — the very ground a patent invalidity search is built to exploit.

That clarity is why a large share of cases settle soon after the ruling. Both sides can finally price the dispute. It also shapes the doctrine of equivalents analysis, since the literal scope fixed here sets the starting point for any equivalents argument.

The battle over claim meaning is no longer confined to the courthouse. Since 2018, the Patent Trial and Appeal Board applies the same Phillips standard in AIA proceedings such as inter partes review, rather than the broader reading it once used. That alignment matters strategically: a construction you win or lose at the PTAB can echo in parallel district-court litigation, and vice versa. Anyone weighing an inter partes review should map the claim-construction positions in both forums before filing.

On appeal, the stakes stay high. Under Teva Pharmaceuticals v. Sandoz, 574 U.S. 318 (2015), the Federal Circuit reviews the ultimate construction without deference (de novo) but reviews any subsidiary findings of fact for clear error. In plain terms: the legal reading gets a fresh look on appeal, so getting the record right at the hearing is critical.

6 Keys to Winning the Terms That Matter

A Markman hearing is not won by arguing every word. It is won by choosing the right fights and grounding them in the patent. Six moves make the difference:

1. Pick case-dispositive terms. Fighting over ten terms when two decide infringement dilutes your credibility and the judge’s attention.
2. Build the story from the specification. Show the judge where the patent teaches your meaning before you reach for outside sources.
3. Mine the prosecution history — both yours and any related applications — for statements that lock in, or give away, scope.
4. Watch for prosecution history estoppel and disclaimer; a narrowing argument made to the examiner can haunt you here.
5. Align your technical expert early so extrinsic testimony reinforces, rather than contradicts, the intrinsic record.
6. Choose plain-and-ordinary meaning or a special definition deliberately — each carries risk, and the right call depends on how the accused product and the prior art line up.

Common Claim Construction Mistakes

The errors that cost parties their cases are usually strategic, not technical. They rarely come from misreading the science; they come from picking the wrong battles or forgetting what the file history already says. Watch for these:

• Disputing too many terms and burying the ones that actually matter.
• Proposing a broad construction to win infringement, only to walk the claim straight into invalidating prior art.
• Ignoring the prosecution history until the other side quotes it back to you.
• Litigating by dictionary while the specification says something else.
• Treating the hearing as a formality rather than the main event — and arriving without a clean claim chart tying terms to the accused product.

How PerspireIP Can Help

PerspireIP supports litigation teams before and through the Markman stage — prior-art and invalidity searching, element-by-element claim charts, and technical analysis that ties your proposed constructions to the specification and the accused product. We help you find the terms worth fighting for and the evidence that wins them. Talk to our team about your matter.

This article is general information, not legal advice; consult a qualified attorney for your situation.

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