Yesterday's Board of Patent Appeals and Interferences (BPAI) decision in Ex Parte Knox confirms what I've always thought about a "no motivation to combine" argument after the decision of KSR Int'l Co. v. Teleflex, Inc, - it's a narrow argument that doesn't have much punch.
The case of Ex parte Knox involved a computer program invention. The Examiner rejected the claims for being obvious in light of two prior art references - Lai and Bradshaw - under 35 U.S.C. § 103(a). Appellants presented a standard "no motivation to combine" argument.
The Board rejected this argument, first reciting case law that is often recited in BPAI decisions:
[I]f a technique has been used to improve one device, and a person of ordinary skill in the art would recognize that it would improve similar devices in the same way, using the technique is obvious unless its actual application is beyond his or her skill." KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007). The test of non-obviousness is not whether one reference can be bodily inserted into another, but, rather, what the references, when considered together, would have suggested to one of ordinary skill in the art, In re Keller, 642 F.2d 413, 425 (CCPA 1981), who is a person of ordinary creativity and not an automaton, KSR, 550 U.S. at 421, and whose inferences and creative steps we may consider, id. at 418.
If you ask me, this is pretty strong language that negates just about any "no motivation to combine" argument. The In re Keller holding appears to eliminate the need to show that two references can even be combined in a technical sense.
In light of the case law cited, the Board concluded the following:
We find that a person of ordinary skill in the art would have recognized that Bradshaw's technique of comparing first checksums with second checksums would improve Lai's file version recording ... We find that a person of ordinary skill in the art, using no more than ordinary skill and creativity, would have recognized that the calculation of a checksum ... could be performed using a checksum algorithm that is insensitive to the ordering of data, such as that taught by Lai.
The lesson learned from this case is that "no motivation to combine" arguments are not among the strongest arguments you can make at the BPAI. Seeing as the case law on combining prior art references is heavily weighted on the side of combining, I would leave this argument at the bottom of your toolbox along with the "non-analogous art" argument. Of course, every practitioner runs into tough situations at some point, and if you have nothing else, digging to the bottom of your toolbox is sometimes necessary.