How Can I tell if Patent Application Was Denied?

It sounds like you have already found the file history at the Patent Office. If not, go to http://portal.uspto.gov/external/portal/pair and use the application serial number or publication number to look up the application. Unless the application is abandoned, you can't really know if it is going to ultimately go through or not. Even if it is abandoned, the applicant could file a petition to revive at some point that would make it active again (although after a year or two this is unlikely to be granted).

A recent case called Bilski has made it more difficult to get a pure business model application through (without tying the business model to a computer, for example, in some way). You have several options. You can wait and see, checking in on the application every six months or so. You could also contact the inventor and try to work out a business solution, such as a license, that would give you peace of mind that if the patent ever is granted you don't have anything to worry about. If you just go forward knowing that you might infringe the application if it becomes a patent, you could be subject to triple damages if you are ever sued for infringement.

As stated above, if an application has been published (18 months after filing) then the prosecution history is available on the PAIR system at www.uspto.gov.

Unless the application has been "abandoned" you should still monitor its status.

You're trying to prove a negative, which, although maybe not entirely impossible in this context, isn't easy. As Mr. Boswell noted, even after abandonment it is possible to revive an application. Practically speaking, if there have been three rejections already, the chances of it going to issue may be pretty small. At some point, what's left in the application might not be worth continuing to pursue.

In addition to what has been mentioned before (continuing to watch, seeking a license), you could also consult with an attorney to discern if your method would even infringe what is left in the application after the repeated amendments. If you do seek a license, payment should be contingent on the patent issuing.

Steve O'Donnell