According to the classical definition available in many developed country jurisdictions, an invention shall be considered as involving an inventive step if, having regard to the prior art, it would not have been obvious to a person skilled in the art (sometimes called the "routine engineer") on the date of filing the patent application or priority. Principally, you as a patent examiner have to assess the following two basic elements:

(1) Prior art and

(2) Non-obviousness.

 

Prior art

Unlike the novelty test, where a quantitative difference between the invention and prior art is sufficient, under the inventive step test, you have to establish a qualitative difference to the prior art.

The information that you can take into account when determining prior art is principally identical with those you consider in the context of the novelty test, except for one difference: Prior art in the context of inventive step is often limited to the publicly available knowledge that an average expert skilled in the art would reasonably consider pertinent in the particular case. Thus, where an average expert has no good reason to use certain publicly available information in the pursuit of a technical solution, such information would usually not be taken into account as a basis for assessing non-obviousness.

As said before, since the inventive step criterion is not defined under the TRIPS Agreement, you as a legislator/patent examiner are free to develop your own strict inventive step standard, which would treat more inventions as obvious and would thus make it more difficult to obtain exclusive rights.

For example, Brazil's National Institute of Industrial Property in September 2008 rejected a patent application by Gilead on the anti-HIV/AIDS drug Tenofovir on the ground that it lacks inventiveness. To read more about this case, please follow the links http://www.aidsmap.com/en/news/945B0134-C898-40D0-9DC6-9C765352E158.asp and http://www.wcl.american.edu/pijip/go/news/brazil-rejects-patent-on-an-essential-aids-medicine.