Know Your Judge Before Construing a Claim in Patent Litigation

In this article for Bloomberg Law, Josh Glucoft analyzes 260 claim terms in 50 different cases in the country’s busiest patent courts to help practitioners consider the best way to construe their claims.

The Bottom Line

• Good claim-construction strategy in patent litigation begins long before appearing before a judge—and should include researching which judge is hearing the case.
• The length of a claim term selected for construction could have as big of an effect on the outcome of the argument as the specific words used.
• Patentees and alleged infringers will want to focus on different aspects of the claim construction to make their case.
• In patent litigation, the claim construction process is often a summary judgment proceeding in disguise. Think of it like real property: If the deed to a parcel of land is clear about the boundaries such that it is readily apparent that an alleged trespasser hasn’t stepped over the property line, then summary judgment is assured. Good claim construction strategy is therefore critical.

To help determine the best strategy during this critical phase of a case, I analyzed the constructions of more than 260 claim terms in 50 different cases from orders issued in 2024. One key takeaway from this analysis is that good claim-construction strategy starts long before any briefs are drafted, and sophisticated litigants should put real thought into the terms they select for construction in the first place.

Patent owners tend to prefer uneventful claim construction orders that don’t move the property lines of their patented inventions for fear that the scope of their patent rights will narrow. Patent owners therefore typically argue for constructions that maintain the preexisting claim language verbatim, often by advocating for a construction of “plain and ordinary meaning.”

By contrast, alleged infringers typically advocate for meatier constructions that expressly define or clarify the claim language, believing the court’s elaboration will provide a useful hook for non-infringement purposes (or, somewhat less commonly, invalidity purposes).

The parties’ claim construction goals therefore diverge: Patent owners typically want the term’s “plain and ordinary” meaning with no express definition provided, and alleged infringers typically want elaborations that go beyond what otherwise appears in the claim.

Courts generally defer to the parties to select which terms to construe, and as discussed below, a party’s success may depend greatly on which terms are selected for construction. Multiple dimensions could be analyzed to help optimize claim term selection, but this initial analysis focuses on data regarding the length of identified claim terms, specifically whether the term to be construed was just one word or a multi-word phrase.

Impact on Outcomes

One reason to think this length factor might affect outcomes is the following guidance from the US Court of Appeals for the Federal Circuit in Phillips v. AWH Corp., the seminal case regarding the process of claim construction:

In some cases, the ordinary meaning of claim language as understood by a person of skill in the art may be readily apparent even to lay judges and claim construction in such cases involves little more than the application of the widely accepted meaning of commonly understood words. In such circumstances, general purpose dictionaries may be helpful.

Almost every English word has a definition in a general or technical dictionary, so in most cases a court could theoretically look up the definition of that single word and resolve any dispute with a prepackaged claim construction, thus readily providing express constructions for nearly every single-word term—generally contrary to most patentees’ preference.

However, dictionaries generally are not needed for most communications because there is usually a shared understanding of individual words, so a “plain and ordinary” construction would suffice for all but the most esoteric words—generally aligning with most patentees’ preference to construe terms as no more than “plain and ordinary.”

For example, it probably isn’t necessary to run to the dictionary to define “table” to determine whether a product is a “table” for purposes of infringing a patent covering a table. A court could be satisfied with “plain and ordinary meaning” because everyone already knows what a table is.

But the Federal Circuit’s guidance doesn’t seem readily applicable to multi-word phrases, which generally don’t have dictionary definitions nor broadly shared colloquial understandings. Therefore, a reasonable hypothesis is that whichever way the Federal Circuit’s guidance might have pushed the approach to single-word terms, we might not see the same approach to multi-word phrases.

What Judges Say

To assess how term length impacted outcomes, I used data from constructions issued by six judges from four districts with some of the busiest patent dockets in the country: the Western District of Texas, Eastern District of Texas, District of Delaware, and Central District of California.

Based on that data in aggregate, it appeared that single-word terms were 15%-20% more likely to be expressly construed than multi-word phrases, which would seem to imply that patent owners would likely favor multi-word phrases while alleged infringers would likely favor single words.

But one judge in this sample set was responsible for a disproportionately large number of construed terms. Removing that judge’s constructions from the data yielded results for the “average” judge that were nearly the same for both one-word terms and multi-word phrases.

The overrepresented judge is closely in line with the average judge regarding one-word terms, but is nearly twice as likely as the average judge to construe multi-word phrases as “plain and ordinary.”

The implication appears to be that the length of the claim term selected for construction could have a real effect on the likelihood of obtaining a “plain and ordinary” construction, but that likelihood varies substantially by your particular judge.

The analysis above doesn’t include two-word claim terms because it was unclear how the Federal Circuit’s guidance might affect courts’ approach to construing two-word terms. But the underlying story turned out to be the same.

Excluding the overrepresented judge from the sample set, we find that the “average” judge takes roughly the same approach regardless of how long the term is, construing all of them as “plain and ordinary” a little more than a third of the time. In other words, the average judge generally isn’t affected by the length of the term identified for construction.

But the overrepresented judge approaches two-word terms much more like multi-word phrases with three or more words and is significantly more likely to construe such two-word terms pursuant to their “plain and ordinary” meaning.

Thus, two-word terms aren’t treated like a hybrid falling somewhere in between other terms; rather, the “average” judge appears insensitive to term length, while at least one prolific judge appears sensitive to term length and approaches two-word terms like other multi-word phrases.

Implications for Strategy

At least with some judges, patentees seeking plain-and-ordinary constructions might benefit from selecting more multi-word phrases for construction rather than single-word terms and, to the extent possible, contextualizing disputes over single words as actually disputes over longer phrases.

Conversely, alleged infringers seeking express constructions might benefit from selecting more single-word terms for construction and, to the extent possible, distilling disputes over longer phrases to disputes focusing on just a single word within that phrase.

This analysis didn’t bucket claim terms by category of statutory subject matter (for example, article of manufacture versus method claims), nor did it analyze claim terms by field (for example, pharmaceutical versus computer science). Future work might dive into those niches, so stay tuned.