The teaching-suggestion-motivation (TSM) test is currently used by the United States Court of Appeals for the Federal Circuit to determine if two or more prior art references can legitimately be combined during the § 103 obviousness inquiry. The TSM test enjoys a long, rich history predating the Federal Circuit, and even its predecessor, the United States Court of Customs and Patent Appeals (CCPA). With the changing conceptions of “invention/obviousness,” originally coined “invention” and later codified as “obviousness,” the TSM test coevolved. The primary benefit of this coevolution is a test for obviousness that operates in a manner consistent with the principles of Graham while at the same time providing a pragmatic method which could be used in proceedings of the patent office and courts alike.

The TSM test was identified early-on as one method of evaluating the legitimacy of combining multiple references. The other important recurring concepts relevant to “invention/obviousness” were also identified surprisingly early; most before 1900. However, consistent use of the TSM test would not come about until much later starting in the Court of Customs and Patent Appeals.  It is fair to say increased reliance on the TSM test is largely in response to the pernicious problem of hindsight reconstruction.  As patent litigation continued to evolve in the CCPA and then Federal Circuit, so did the rigor with which the TSM test was consistently applied.  Applied rigorously, the TSM test proved to be a valuable tool for reaching rational, defensible obviousness determinations consistent with Graham while avoiding hindsight reconstruction.

The elegance of the TSM test can best be appreciated by tracing its development, and observing TSM’s development as the courts consistently battled with hindsight reconstruction.

This paper is one of two papers that form the basis for Professor Hollaar's amicus brief to the Supreme Court in the KSR v. Teleflex patent case. The second is "Unclear and Unconvincing: How a misunderstanding led to the heightened evidentiary requirement in patent litigation" by Hollaar and Knight.

This page was last revised on September 30, 2006.