Federal Circuit Reinforces Indefiniteness Standard for Terms of Degree

In Akamai Technologies, Inc. v. MediaPointe, Inc., the Federal Circuit reaffirmed that claim language employing terms of degree such as “optimal” and “best” must be supported by objective and exclusive boundaries in the specification to satisfy the definiteness standard under Nautilus, Inc. v. Biosig Instruments, Inc. The decision provides critical drafting guidance for patent prosecutors and in-house counsel, particularly in technology and AI-related patents where qualitative or performance-based terminology is common.

The patents at issue described systems and methods for routing streamed media content over an “intelligent distribution network.” The US District Court for the Central District of California found claims indefinite where they required determining the “best” or “optimal” routes and nodes, concluding that the specification failed to provide consistent objective criteria for assessing those terms, a finding the Federal Circuit would go on to affirm.

The Federal Circuit characterized the claim language explicitly as “language of degree”:

The language at issue here plainly is language of degree with a facially discretionary standard. ‘[T]he written description is key to determining whether a term of degree is indefinite.’. . . Language of degree, like the language at issue here, is indefinite unless, ‘when read in light of the specification and the prosecution history, [it] provide[s] objective boundaries for those of skill in the art.’[1]

Applying the Nautilus test, the court held:

We conclude that . . . the patents here do not give the required objective boundaries for determining what is ‘optimal’ or ‘best.’ . . . [The claims do] ‘not provide a reasonably clear and exclusive definition’ of ‘optimal’/‘best’ or, therefore, provide ‘an objective boundary.’[2]

The court explained that while the claims referred to measurable factors such as latency, number of hops, and reliability, the specification also invited consideration of such open-ended factors as network bandwidth, cost, or time of day without explaining how to weigh or reconcile them. This lack of a consistent standard rendered the terms indefinite.

KEY TAKEAWAYS FOR IN-HOUSE PATENT PROSECUTORS

Define Terms of Degree with Objective Metrics

When using evaluative terms such as optimal, best, efficient, high quality, or improved, ensure the specification discloses how such qualities are measured or determined. A person of skill in the art reading the specification in light of the prosecution history must be able to determine the objective boundaries of the claim.

The court has emphasized that these terms must have an “informed and confident choice” that is available among the many definitions that can be assigned to the term. To meet this requirement:

• Use quantitative thresholds where possible (e.g., latency <100 ms, throughput >10 Mbps)
• When using relative terms such as “best” or “optimal,” provide algorithms or formulas specifying ranking or selection criteria
• When describing ways to assess whether a limitation is met or failed, use defined experimental protocols or performance benchmarks (e.g., speed, latency, or reliability tests)

Provide Exclusive and Consistent Boundaries

The Federal Circuit emphasized that objective boundaries must also be exclusive, and the specification cannot leave the determination open to multiple conflicting interpretations. Avoid phrases such as “based on one or more factors” without identifying which factors control and how they interact.

Avoid Open-Ended Language

Disclose how conflicting parameters (e.g., latency vs. reliability) are resolved. For example, if there are multiple criteria for determining what a most optimal route is, include rules in the specification about how to resolve conflicts when the multiple criteria suggest different optimal routes. Make sure to contemplate all possible outcomes. Absent a clear rule, claims risk being found indefinite even if the relevant parameters are known.

Document Objective Evaluation Frameworks

Support terms of degree with experimental data, standardized metrics, or explicit definitions showing that skilled artisans would reach consistent results. If there are multiple methods for determining whether a claim limitation has been met and these multiple methods would lead to different results, the claim limitation may be held to be indefinite.

Conduct Drafting Audits for Vulnerable Terms

In-house teams should audit specifications for subjective or comparative language and revise to add measurable anchors or defined testing methodologies.

LOOKING AHEAD

The Akamai decision provides a cautionary precedent for technology and AI-related patent portfolios. For in-house counsel:

• Portfolio risk review: Identify issued patents or pending applications using unbounded evaluative terms (e.g., optimized, enhanced, efficient) and assess exposure under Nautilus.
• Prosecution strategy: Include dependent claims specifying quantitative parameters to preserve fallback positions.
• Drafting discipline: Collaborate early with inventors to identify measurable criteria or algorithms that can define subjective improvements.
• Litigation readiness: Expect defendants to invoke Akamai and Interval Licensing to challenge functional or qualitative claim terms.

The ruling underscores a tightening of the definiteness doctrine for terms of degree. Patent prosecutors should anticipate heightened examiner and litigation scrutiny where claims use qualitative or functional language. Embedding objective, reproducible, and exclusive criteria in the specification remains the most effective defense against indefiniteness challenges.