Background
Interval Licensing LLC held patents on a technology described as an “attention manager” — a system that acquires content from providers, schedules its display, and presents information to users on a peripheral display without disrupting the user’s primary task. The patents described displaying content in an “unobtrusive manner” that would not interfere with what the user was focusing on — for example, showing news or weather updates in the corner of a screen while the user worked on another application. Paul Allen’s Interval Research Corporation developed the technology in the mid-1990s, and Interval Licensing held a broad portfolio of Internet-era technology patents.
Interval sued AOL and Yahoo (among others) for infringement. The Western District of Washington found numerous patent claims indefinite — particularly those using the phrase “in an unobtrusive manner” — and found non-infringement on other claims based on the district court’s claim construction of “attention manager.” The district court’s indefiniteness ruling came before the Supreme Court decided Nautilus, Inc. v. Biosig Instruments (2014), which rejected the Federal Circuit’s then-existing “not amenable to construction” or “insolubly ambiguous” indefiniteness standard in favor of requiring that claims inform, with “reasonable certainty,” those skilled in the art about the scope of the invention.
The Court’s Holding
The Federal Circuit applied the newly articulated Nautilus “reasonable certainty” standard and affirmed that the challenged claims were indefinite. The court acknowledged that terms of degree — like “unobtrusive” — are not inherently indefinite; patent law regularly accommodates terms that define relative or qualitative properties. However, to be definite, such terms must provide adequate guidance to skilled artisans about what falls within and outside the claim scope when read in the context of the specification and prosecution history.
The court found that the term “unobtrusive manner” in the context of Interval’s patents failed this test. The specification provided no objective standard for measuring what was or wasn’t obtrusive — it offered examples but did not anchor the concept to a technical threshold or reference point that a skilled artisan could use reliably. The claims thus failed to inform with reasonable certainty what the claim covered. This was one of the first Federal Circuit decisions applying Nautilus on the merits, and it demonstrated that the new standard would result in genuine differences in outcome for some patents compared to the old “insolubly ambiguous” test.
On claim construction, the court disagreed with the district court’s construction of “attention manager” and “instructions,” vacated the non-infringement judgment on four claims, and remanded those claims for further proceedings — ultimately leading to a subsequent § 101 eligibility ruling in 2018 that found those claims abstract.
Key Takeaways
- The Nautilus “reasonable certainty” standard is more demanding than the old “insolubly ambiguous” test: claims that were marginally definite under the old standard may be indefinite under Nautilus if they fail to inform skilled artisans with reasonable certainty about claim scope.
- Terms of degree (like “unobtrusive,” “substantial,” “significant”) are not automatically indefinite, but they must be anchored to an objective or technical referent — the specification must provide meaningful guidance on how to apply the qualitative term.
- Interval Licensing is one of the first Federal Circuit decisions applying Nautilus on the merits, establishing that the new standard has bite and will invalidate claims with poorly anchored qualitative limitations.
- The decision illustrates the dual indefiniteness/claim-construction challenge faced by many early Internet-era software patents: vague functional language that seemed adequate in the 1990s now faces heightened scrutiny under Nautilus.
Why It Matters
Interval Licensing v. AOL was an early and important test of the Nautilus indefiniteness standard’s practical effect. After the Supreme Court tightened the legal test for definiteness in June 2014, patent litigants and patent prosecutors immediately needed to understand how the Federal Circuit would apply “reasonable certainty” to existing patents. The Interval Licensing decision showed that Nautilus matters — it produced a different outcome than the prior standard would have for patents using functional, qualitative claim language without an objective measuring standard.
For patent drafters, the case reinforced the importance of providing objective technical reference points for any qualitative claim term. Describing what is “unobtrusive” by reference to display brightness thresholds, timing parameters, or user interaction data — rather than relying on a commonsense understanding of the word — would give claims far stronger definiteness footing after Nautilus. For patent challengers, the case confirmed that even patents that survived validity challenges for years under the old standard can be vulnerable to indefiniteness attacks under Nautilus if their key claim terms lack objective anchors in the specification.