Patent Claim Interpretation and Information Costs

35 Pages Posted: 19 Oct 2004 Last revised: 6 Apr 2009


The concept of invention is crucial to patent law. Inventions of patentable quality are what the patent system is trying to encourage. And in order to provide this incentive to produce such inventions, the patent system must provide protection for the invention. Furthermore, everyone in the patent system must know the contours of the protected invention to make determinations on issues of the invention's infringement and validity. The problem the patent system runs into is that inventions are difficult to define - this difficulty stemming in part from the intangible nature of inventions. Inventions are essentially ideas, information, concepts. While an invention has physical manifestations, these are merely examples of the invention. An invention's inherent lack of physicality, lack of thingness, makes it tough for any observer to comprehend.

Patent law, therefore, encounters an information cost problem. Everyone in the patent system needs information about the invention, but the invention's intangibleness makes this information costly to produce, collect, and comprehend. Patent law responds by enforcing certain information producing rules. These rules are located in 35 U.S.C. section 112 and dictate the creation of the patent document itself. The onerous is placed on the patentee to provide a specification and one or more claims for the whole world to see. The specification must include a description of the invention, how to make and use the invention, and any best way of practicing the invention known to the inventor. The patent must also include one or more claims that specify the borders of the invention the patentee wishes to protect.

These information producing rules do not completely rectify the information cost problem in defining the edges of patent protection. The patent claim, while meant to inform everyone about the boundaries of the grant of exclusivity, must be interpreted to be of any use. Claim interpretation places the claims in context to resolve a given dispute. The method of claim interpretation presents information cost issues of its own - costs associated with the production, collection, and processing of information in order to define the exact area of exclusivity given by the patent claim. And the lower the information costs incurred during this process, the easier it is for any actor in the patent system to comprehend the most crucial aspect of a patent - its scope of exclusivity.

This Article addresses the information cost issues presented by the process of interpreting the claimed invention. This Article takes a specific look at the information costs generated when using two different information tools - the specification and external definitional sources such as dictionaries. This Article concludes that full use of the specification early in the claim interpretation process minimizes information costs. The information in the specification is already tailored to and in context with the claim under interpretation. In addition, the specification provides invention-specific information in a low cost fashion and includes information that caters to an interpreter's familiarity and ease with understanding tangible things. In contrast, a claim interpretation methodology that employs a heavy presumption in favor of external definitional sources introduces information costs. The selection and processing of these definitional sources can be extremely costly. Furthermore, such an approach squanders the cost savings gained by using the whole specification early in the interpretation process. This Article further concludes that any interpretation methodology should consider the information costs it imposes on both the patentee and any patent observer, keeping in mind the invention-specific information patent law already requires to be produced.

Keywords: Patent, Claim, Claim Interpretation, Claim Construction, Information Costs, Specification, Methodology

JEL Classification: D23, D80, D83, K11, K20, K30, K40, O31, O34

Suggested Citation

Cotropia, Christopher Anthony, Patent Claim Interpretation and Information Costs. Lewis & Clark Law Review, Vol. 9, 2005, Tulane Public Law Research Paper No. 04-08, Available at SSRN:

Christopher Anthony Cotropia (Contact Author)

University of Richmond - School of Law ( email )

28 Westhampton Way
Richmond, VA 23173
United States

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