Inventorship is determined by criteria specified in the U.S. patent law. U.S. patents are granted only to the true inventor(s). An inventor is that person who, alone or in combination with others, discovers any new and useful process, machine, manufacture, or composition of matter, or any new and useful improvement thereof. Authorship does not mean inventorship. The correct listing of inventors is very important. A patent can be invalidated for the failure to list all proper inventors. Inventors may need to be added to an application or initially named inventors removed from the patent based upon the final claims in the patent.
Conception, according to the U.S. patent law, involves the formulation, in the mind of the inventor(s), of a definite and permanent idea of the complete and operative invention. An invention would be complete and operative if the description would enable one of ordinary skill in the art to construct the apparatus or perform the method without extensive research or experimentation. If extensive research or experimentation is necessary to reduce the invention to practice, then the conception was probably not complete. Likewise, if no significant difficulties were encountered and few if any deviations were made from the mental plan, the conception was probably complete, and the person or persons responsible for the plan are the true inventors. If deviations were required, those responsible for the deviations could be joint inventors.
Reduction to Practice can be accomplished two different ways. Actual reduction to practice is a physical embodiment of the invention for its intended use. Constructive reduction to practice is reasonable theoretical proof that the invention will work, which is described in writing.
First Publication or Oral Disclosure is the first time any member of the general public, without restriction of confidentiality, would have been able to legally gain access to your written or printed enabling description of the invention, or the first oral presentation to the general public. An offer to sell a product based on the invention is a public disclosure, but description of the invention in a proposal to a funding agency is not, if there is a confidentiality provision or reasonable expectation of confidentiality in the proposal process.