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An Empirical Analysis of District Court Claim Construction Decisions, January to December 2009

By James R. Barney and Charles T. Collins-Chase

In the past decade, a number of studies have scrutinized the Federal Circuit’s rate of reversal of district court claim construction rulings. To date, however, there has been little empirical research focusing on district court claim construction decisions themselves. Although district court statistics represent only a “slice in time” before appeal, they are nevertheless important to litigants and trial counsel, who must make various tactical decisions and cost-benefit analyses at the district court level long before considerations of appellate reversal rates come into play.

This article explores claim construction outcomes at the district court level, including patentee win rates on an element-by-element basis, win rates for broad constructions versus narrow constructions, and win rates by jurisdiction and type of argument. To accomplish this goal, we examined 211 district court Markman decisions from 2009, which collectively construed a total of 1858 disputed claim terms. We culled data from these decisions and performed various statistical analyses to arrive at the outcomes reported herein.

This paper is divided into five parts, including this Introduction. In Part II, we provide a brief background of the current state of claim construction law, including litigation strategies involved in claim construction. In Part III, we explain the methodology used in this statistical study, including limitations of the study. In Part IV, we report the statistical outcomes of our study. In Part V, we summarize our findings and suggest conclusions that can be drawn from them.

Posted in Articles.

January 21, 2011 Cite: 2011 Stan. Tech. L. Rev. 2