The PTAB Declaration That Gets Credited

The difference between a PTAB declaration the Board credited and one it discounted is not a question of credentials. The credit-rate distribution across repeat experts has the same range of pedigrees at the top and at the bottom. What separates them is how the document is built. The Board's final written decisions are explicit about the construction patterns it credits, and just as explicit about the failure modes that produce a no-weight finding.

This post is a read of those patterns across repeat-expert declarations on WitnessLens, with the median credit rate near 75%, the top 38% of repeat experts sitting at 80% or above, and the bottom 19% sitting below 20%.

Claim-by-claim mapping

The first separator is whether the declaration walks each challenged claim, limitation by limitation, and ties each limitation to a specific disclosure in the prior art. The credited declarations do this in a numbered or tabular form. The discounted declarations gesture at the prior art generally and then state a conclusion.

The Board's discount language for the second pattern is familiar in the decisions. It cites the proposition that a declaration that does not "explain how" the prior art teaches the limitation, or that "summarily concludes" the limitation is met, is entitled to little weight. That language is doing the operative work in a large fraction of the bottom-tail decisions.

Claim-by-claim mapping is also the structure that survives a partial obviousness combination. When the Board credits some limitations and not others, a mapped declaration lets the petitioner argue the remaining limitations on the record. A declaration that did not separate the limitations cannot be partially salvaged.

Citation density and exhibit support

The second separator is citation density. The credited declarations cite a specific exhibit, page, column, and line for each prior-art assertion. The discounted declarations cite an exhibit number with no internal pin.

This is not a stylistic preference. The Board's standard practice is to verify the expert's citation against the prior-art reference. When the citation is precise, the verification is fast and the testimony reads as supported. When the citation is general, the Board's options are to find the support itself, to credit the expert on faith, or to discount. The third option is the one the Board defaults to under the framework it applies to expert declarations.

Exhibit support is the same point on the secondary-considerations side. A declaration that asserts commercial success or long-felt need without an exhibit, or with an exhibit that does not name the patented feature, is a declaration that does not survive a final written decision contested on those grounds.

POSITA framing

The third separator is how the declaration handles the level of ordinary skill in the art. The credited declarations define the POSITA, state the expert's basis for the definition, and then opine through the POSITA's perspective at the relevant time. The discounted declarations either skip the POSITA definition or define it in a way that does not match the expert's later analysis.

A common failure mode is a high-credentials expert who defines a POSITA with substantially less education than the expert and then proceeds to opine from the expert's own perspective. The Board catches this. The discount is not about credentials; it is about whether the opinion is anchored to the framework the declaration set up.

Osseo Imaging, decided at the Federal Circuit in 2024, clarified that POSITA qualification is judged on present knowledge, not on whether the expert held that knowledge at the time of the invention. That clarification does not change the drafting discipline. The POSITA definition still has to be coherent, and the opinion still has to track it.

The conclusory-testimony failure mode

The most common reason a declaration in the bottom tail of the credit distribution gets discounted is not a methodology defect. It is conclusory testimony. The expert states the conclusion, asserts that the conclusion follows from training and experience, and stops.

The PTAB has been direct about this since at least Xerox Corp. v. Bytemark, Inc., where the Director's review in February 2023 reinforced that an unsupported expert assertion that "merely repeats, verbatim, the conclusory assertion" of the petition is entitled to little weight. The Director's review made the point as a matter of how the Board allocates its analytic burden: the expert's role is to support the assertion, not to restate it.

The drafting implication is that every paragraph asserting a technical conclusion should be followed by either a prior-art citation, an exhibit reference, or a worked explanation of why a POSITA would reach that conclusion. A declaration that has fewer support paragraphs than conclusion paragraphs is, on average, in the discount band.

A drafting checklist

The construction patterns that separate the high-credit declarations from the low-credit declarations reduce to a short checklist.

Map each challenged claim limitation by limitation, in a numbered or tabular format. Cite the prior art by exhibit, page, column, and line for each assertion. Define the POSITA, state the basis for the definition, and write the opinion in that voice. Support each technical conclusion with a citation, an exhibit, or a worked explanation rather than with credentials. Avoid restating the petition's conclusory language as if restatement were support.

None of this is novel. All of it is on the face of the decisions that credited and discounted the declarations on WitnessLens. The drafting discipline is the variable.

A note on the data

The credit-rate figures cited above (median near 75%, top cluster at 80% and above representing roughly 38% of repeat experts, bottom cluster below 20% representing roughly 19% of repeat experts) are drawn from repeat experts with at least five tracked PTAB proceedings on WitnessLens. The Xerox v. Bytemark Director's review citation is to the February 10, 2023 sua sponte Director review decision (IPR2022-00624, Paper 12), affirming and designating as precedential the Board's August 2022 institution denial. Cohort and credit-rate definitions are described on the methodology page.