Research and commentary from WitnessLens on patent expert witness selection, PTAB outcomes, and Daubert analysis.
What active patent expert witnesses charge, how rates vary by expert type, how rates move over time, and where the disclosed number stops being a useful retention signal.
Read post →Q1 2026 patent Daubert rulings held the post-amendment pattern, with damages experts continuing to draw the largest share of motions.
Read post →How the PTAB treats secondary-considerations expert testimony, where the nexus requirement tightens the analysis, and what the Board credits.
Read post →The Federal Circuit's expectations for doctrine-of-equivalents expert testimony and what happens when the linking is missing.
Read post →What 2025 aggregates revealed about Daubert outcomes, PTAB credibility, hourly rates, and side-mix for patent expert witnesses.
Read post →Two years after the December 2023 amendment, patent Daubert outcomes show measurable tightening, with most of the change concentrated at the partial-exclusion margin.
Read post →PTAB depositions run seven hours, are limited to the subject matter of the declaration, and produce transcripts that go directly into the record, which changes how prep and questioning should work.
Read post →The Federal Circuit affirmed a district-court JMOL reducing a $10 million patent damages verdict to $1 in nominal damages after the patentee's damages expert was excluded for failing to apportion a portfolio license to the asserted patents.
Read post →Ten checks an IP partner should run before retaining a patent expert, from PTAB credit rate to deposition history to the expert's adverse-firm footprint.
Read post →H1 2025 Daubert merits rulings in patent cases held the post-amendment pattern: partial exclusions roughly twice as common as full exclusions, with damages experts taking the hardest hits.
Read post →Expert testimony is gated by Rule 702 in district court and weighed for credibility at the PTAB, and the procedural gap changes how declarations should be written for each forum.
Read post →Apportionment is the rule; the entire market value rule is the narrow exception; damages experts who confuse the two get excluded, and the post-EcoFactor record makes that exclusion more frequent.
Read post →The en banc Federal Circuit vacated a $20 million patent damages verdict because the expert relied on unilateral whereas recitals in three lump-sum settlement licenses as evidence that the licensees had agreed to a per-unit rate.
Read post →The Federal Circuit has now confirmed in two cases that an expert's POSITA qualification is judged on present knowledge rather than on whether the witness held that knowledge at the time of the invention.
Read post →The difference between a credited PTAB declaration and a discounted one is not a question of credentials; it is a question of how the document is built, and the construction patterns are visible across the credit-rate distribution.
Read post →Fourteen months after the December 2023 amendment, the proponent's burden of admissibility by a preponderance of the evidence is showing up in patent Daubert orders as tighter gatekeeping on damages and a more demanding read of methodology disclosures.
Read post →The 2024 record across PTAB declarations and district court Daubert rulings shows tighter gatekeeping, a partial-exclusion regime that dominates full strikes by roughly two to one, and a credibility distribution that is wider than most retaining partners assume.
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