Datamize v. Plumtree: Why Aesthetically Pleasing Was Fatally Indefinite

Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342 (Fed. Cir. 2005), is the case lawyers cite when a patent claim rests on a word that sounds like a matter of taste. Decided August 5, 2005, in an opinion by Judge Prost, it invalidated as indefinite a claim that required an electronic interface to be “aesthetically pleasing.” The court held that a purely subjective term, one whose satisfaction depends on the eye of the beholder rather than any objective measure disclosed in the patent, cannot inform the public of the boundaries of the claimed invention. Two decades later Datamize remains the leading authority on subjective claim terms, cited in nearly every fight over a term of degree.

At a glance

• Case: Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342 (Fed. Cir. 2005)
• Decided: August 5, 2005; opinion by Judge Prost (panel: Clevenger, Bryson, Prost); summary judgment of invalidity affirmed
• Holding: A claim term (“aesthetically pleasing”) that is purely subjective and lacks any objective anchor in the intrinsic record is indefinite under 35 U.S.C. § 112 ¶ 2 because it fails to inform the public of the scope of the claim.
• Significance: The controlling case on subjective claim terms and terms of degree, requiring an objective standard for measuring the term’s satisfaction.

The definiteness requirement

The second paragraph of 35 U.S.C. § 112 (now § 112(b)) requires that a patent’s claims “particularly point out and distinctly claim” the invention. The requirement serves a public-notice function: claims mark the boundaries of the exclusive right, and competitors, courts, and the public must be able to tell what is inside and what is outside. A claim that fails to do so is invalid as indefinite.

When Datamize was decided, the Federal Circuit framed the inquiry through the “insolubly ambiguous” standard: a claim was indefinite only if it was not amenable to construction or was insolubly ambiguous. That formulation set a forgiving bar and generally saved claims that could be given some construction. Even under that lenient standard, the “aesthetically pleasing” limitation failed, which is part of why the decision has such staying power.

The patent and the claim

Datamize owned U.S. Patent No. 6,014,137, titled “Electronic Kiosk Authoring System.” The patent described software that let a non-programmer design the user interfaces displayed on electronic kiosks, the interactive screens found in stores, airports, and public spaces. To keep the many screens produced by different authors visually consistent and attractive, the system constrained the author’s choices using predefined design elements.

The sole independent claim recited a method whose steps included providing a menu of “aesthetically pleasing” interface screen elements. The phrase was not incidental. It was a limitation of the claim, meaning that to infringe, an accused system had to use elements that were “aesthetically pleasing,” and to be valid the claim had to make clear which elements those were. Plumtree moved for summary judgment that the claim was indefinite.

The court’s reasoning: subjectivity without a standard

The Federal Circuit affirmed the district court’s holding that the claim was indefinite. Its reasoning proceeded in two moves.

First, the court recognized that “aesthetically pleasing” is inherently subjective. Whether a screen layout is pleasing to look at is a matter of individual taste. What one user finds attractive another finds cluttered or dull. A claim limitation that turns on such a judgment gives no fixed content unless the patent supplies some external yardstick.

Second, and decisively, the court searched the intrinsic record for that yardstick and found none. The specification described features intended to produce consistency and visual appeal, but it never defined what made a screen aesthetically pleasing or supplied any objective criteria by which the judgment could be made. The court was careful to say that the problem was not that beauty is involved. The problem was the total absence of a workable objective standard. Because neither the claims, the written description, nor the prosecution history told a skilled artisan how to determine whether a given interface element satisfied the limitation, the scope of the claim depended entirely on the unconstrained opinion of whoever happened to be judging. That is exactly the uncertainty the definiteness requirement forbids.

The court also rejected the argument that the aesthetic judgment could be supplied by the patentee’s own subjective preferences or by a system designer’s taste. Tying claim scope to one person’s opinion does not cure indefiniteness; it entrenches it, because the public cannot know or replicate that private judgment.

Terms of degree and the objective-anchor rule

Datamize did not hold that subjective-sounding words are always fatal. The Federal Circuit has long tolerated terms of degree, words like “substantially,” “about,” or “close,” when the intrinsic record gives them workable meaning. The governing principle that Datamize crystallized is that a term of degree or a subjective term is acceptable when the specification provides “some standard for measuring that degree.” Where the patent supplies objective criteria, examples, or a reference point, even an evaluative term can be definite. Where it supplies nothing but the observer’s taste, the term fails.

That distinction is why Datamize is cited on both sides of indefiniteness disputes. Patentees invoke it to argue that their specification supplies the objective anchor that Datamize’s did not. Challengers invoke it to argue that a claim term is naked subjectivity. The case supplies the framework, and the outcome turns on how much objective content the particular record contains.

After Nautilus: the standard changed, the teaching survived

In Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898 (2014), the Supreme Court rejected the “insolubly ambiguous” formulation as too permissive and held that a claim is indefinite if, read in light of the specification and prosecution history, it fails to inform those skilled in the art about the scope of the invention “with reasonable certainty.” That was a tightening of the standard. It made Datamize’s bottom line more secure, not less: a claim that flunked even the forgiving pre-Nautilus test flunks the stricter one all the more clearly. Post-Nautilus decisions on terms of degree, including cases addressing words like “unobtrusive manner” and other evaluative terms, continue to draw on Datamize’s objective-anchor requirement. The vocabulary of the test evolved; the lesson about subjective terms did not.

Open questions

Datamize leaves the hard cases exactly where they are: at the margin. How much objective content is enough to save a subjective-sounding term is not reducible to a formula, and courts reach different results on similar-looking records. The interaction between Datamize and functional claiming under Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015), also remains a live area, since a term can fail for subjectivity or for reciting function without structure. And the treatment of terms that blend technical and aesthetic content, common in design-adjacent software and user-experience patents, continues to generate litigation.

Implications for inventors and businesses

• Anchor evaluative terms to objective criteria. If a claim uses a word of degree or taste, the specification should supply measurable standards, examples, or reference points that let the public tell what falls inside the claim.
• Avoid taste as a claim limitation. Words like “aesthetically pleasing,” “attractive,” or “user-friendly” are dangerous as limitations unless the patent defines them objectively. Prefer functional or structural language that can be measured.
• Build the intrinsic record deliberately. Definiteness is judged on the claims, specification, and prosecution history. Statements made during prosecution can supply, or destroy, the objective anchor a term needs.
• Audit for terms of degree. Portfolios containing evaluative claim language should be reviewed for indefiniteness exposure, especially under the tighter Nautilus standard, and shored up through continuations where possible.

Frequently asked questions

Why was aesthetically pleasing held indefinite? The Federal Circuit found the term purely subjective, with no objective anchor in the claims, specification, or prosecution history that would tell the public what interface designs fall inside or outside the claim. Because whether a screen is aesthetically pleasing depends entirely on the observer’s taste, the claim failed to inform skilled artisans of its scope.

Does a subjective-sounding claim term always render a claim indefinite? No. Terms of degree and even some subjective-sounding words can be definite if the intrinsic record supplies an objective standard for measuring them. Datamize’s problem was that the patent gave no workable standard at all; it left the aesthetic judgment entirely to individual opinion.

Is Datamize still good law after Nautilus? Yes in substance. Datamize applied the older insolubly ambiguous formulation, which the Supreme Court replaced in 2014 with the reasonable certainty standard of Nautilus v. Biosig. Datamize’s core teaching, that a purely subjective term needs an objective boundary, remains routinely cited in terms-of-degree indefiniteness disputes.

Authorities and sources

• Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342 (Fed. Cir. 2005), opinion via FindLaw.
• 35 U.S.C. § 112, definiteness requirement, Cornell LII.
• Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898 (2014), the reasonable-certainty standard, Cornell LII.
• Case brief and holding summary, Quimbee.
• Studicata case brief on facts, issue, and holding, Studicata.
• Williamson v. Citrix Online, LLC, 792 F.3d 1339 (Fed. Cir. 2015), companion functional-claiming authority, opinion via Berkeley Law.