Assessing Inventive Step in Examination

Date Published

Note: The information in this part only applies to standard patent applications with an examination request filed on or after 15 April 2013.  For all other standard patent applications, see Assessing Inventive Step in Examination.


The procedure of courts relies upon the evidence of expert witnesses when seeking an answer to the question "is it obvious?" Unlike courts, examiners do not have access to evidence from the person skilled in the art. Instead, they are required to put themselves "in the shoes of the skilled worker" and make their own assessment of what the notional skilled worker was likely to have done at the priority date. In doing so, they must assess "obviousness" based on their own knowledge and balance of probability considerations - see 2.13.5 Stringency of Tests During Examination.

Such assessment can be difficult. As examiners will inevitably know the claimed solution, they must set that knowledge aside in their assessment of inventive step. The initial consideration of whether a claim is obvious can be coloured by:

  • ex post facto analysis;
  • judging the merit of the invention;
  • the motivation for the invention;
  • failing to recognise that an inventive step requires no more than a scintilla of invention;
  • failing to determine the common general knowledge appropriate to the person skilled in the art; and
  • failing to consider all relevant issues.

Courts have also discussed the problem of ex post facto dissection of the invention. In Meyers Taylor Pty Ltd v Vicarr Industries Ltd (1977) 137 CLR 228 at page 242, Aickin J stated:

"subsequent analysis of the invention - 'the dissection of the invention' - is not helpful in resolving the question of obviousness".

Problem-Solution Approach

An approach used by the courts to avoid ex post facto analysis is the "problem-solution" approach. In HPM Industries Pty Ltd v Gerard Industries Ltd 98 CLR 424 at page 437, Williams J stated:

"If the invention were novel it would nevertheless fail for want of subject matter if in the light of what was common general knowledge in the particular art, it lacked inventive ingenuity because the solution would have been obvious to any person of ordinary skill in the art who set out to solve the problem."

The "problem-solution" approach is based on the question of whether the claimed invention would have been obvious to a person skilled in the relevant art when faced with a particular problem. The approach is the preferred one to apply when considering inventive step, as it reduces the risk of ex post facto analysis.  The problem-solution approach also ensures that the examiner's consideration of whether a claim lacks an inventive step:

  • is valid and sustainable; and
  • identifies all the issues relevant to establishing lack of inventive step.

Applying the Problem-Solution Approach

The problem-solution approach involves the following steps:

a. construe the specification under examination and determine the problem the claimed invention solves (see Determining the Problem).

b. identify the person skilled in the art in the field of the problem (see Identifying the Person Skilled in the Art (PSA)).

c. determine, where applicable, whether in the context of the problem, any pieces of prior art information under consideration are such that the person skilled in the art could be reasonably expected to have combined them (see Could the Person Skilled in the Art be Reasonably Expected to Have Combined the Prior Art Information to Solve the Problem?)

d. determine the relevant common general knowledge (see Common General Knowledge).

e. determine whether, in the context of the problem, the claimed invention is one of:

  • a technical equivalent;
  • a workshop improvement;
  • an obvious selection or special inducement; or
  • an obvious combination of features of common general knowledge.

f. consider whether:

g. if relevant, consider whether there has been a prior perceived need using the tests of:

  • long felt need;
  • failure of others;
  • copying of invention in preference to prior art; and
  • commercial success.

h. an objection of lack of inventive step only arises where it can be shown that a person skilled in the art would, in solving the problem, have taken the necessary steps to reach the claimed solution. In practice, this will be the case if the requirements under c. and e. are met, and those under f. and g. are not met.

Examination Practice

In practical terms, examiners should not undertake a detailed analysis of every issue in each procedural step. Rather, examiners should identify all relevant issues. An inventive step objection must explain all relevant issues, but need not discuss matters that are unlikely to affect the outcome of the objection.

For example, a citation which is clearly a mere technical equivalent (in the context of the problem) of the claimed invention must presumably have fully solved the problem, i.e. the only issues are whether the difference is a technical equivalent in the context of the problem and whether the technical equivalent is common general knowledge.