APAA e-Newsletter (Issue No. 40, April 2024)

Secondary Indicators and Their Use in the Assessment of Inventive Step

Dr Maureen Lobo, Dr Mike Zammit - Spruson & Ferguson (Australia)



The Patents Act[1] defines that an invention is taken to involve an inventive step unless it would have been obvious to a skilled addressee in light of the common general knowledge before the priority date of the relevant claim when considered alone or together with prior art information.[2]

Nicholas J provided a succinct statement of principles relevant to assessing inventive step in Hood v Bush Pharmacy:

“Something may be ‘obvious’ … if it is ‘plain or open to the eye or mind, something which is perfectly evident to the person thinking on the subject’ or something which ‘would at once occur to anyone acquainted with the subject and desirous of accomplishing the end’.

An invention may also be obvious in light of the common general knowledge if the person skilled in the art faced with the same problem as the inventor would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not or (using the language of the ‘modified Cripps question’) if the person skilled in the art would be directly led as a matter of course to take such steps in the expectation that doing so might well produce a useful or better alternative to the prior art.”[3]

​​​​​​​As noted in the Examiner’s Manual,[4] other formulations of the test for inventive step include asking, in the context of the problem the invention is seeking to address, whether the claimed invention is one of: a technical equivalent, a workshop improvement, an obvious selection, or an obvious special inducement.

Secondary indicators of inventiveness

Secondary indicators (also known as ‘signposts’, ‘secondary indicia’, and ‘secondary considerations’) are aspects of an invention that may assist in assessing inventive step. They include matters such as: long-felt need, commercial success, failure by others, and copying of the invention. It has long been recognized that secondary indicators have a role to play in inventive step analysis, and that Australian Courts “should be slow to ignore secondary evidence”, but their significance varies.[5] Ultimately, however, the overarching question of whether or not the claimed invention is obvious still needs to be addressed.[6]  Many secondary indicators are based on economic and motivational factors[7] and can help shed light on the invention.

  1. A long-felt need – based on the idea that inventions fulfil a need, or a want in the industry and that problems would not persist if the solution were obvious.[8] The long-felt need must be appreciated across the industry and not just by the Applicant. Examples of evidence of long-felt need include: (a) Evidence of other’s attempts to solve the problem g., patent applications filed by other companies relating to the same problem[9], and (b) evidence that the problem was worthwhile to solve.[10]
  2. An unfelt need – based on the idea that some inventions may not be the result of extensive research and contemplation, but also of chance, lucky thought, or mere accidental discovery.[11] To justify an unfelt need, the problem solved by the invention must not have been recognized before.
  3. Copying of the invention – based on the idea that there would be no reason to copy an invention if it were obvious.[12] Copying of the invention must have occurred as a direct result of the claimed invention. The inference of an inventive step from copying of the invention may have more significance if the copier could only achieve the desired technical effect by copying the invention.
  4. Commercial success – based on the idea that the industry would not be so receptive to adopting an invention if it were obvious. Importantly, commercial success must be of the claimed invention and not of another invention or a technical embodiment made possible by the invention. Other factors such as price, good marketing, and the commercial environment can limit inferences from commercial success. Examples of evidence of commercial success include:
    • Communication between industry members and with customers
    • Sales data and market share[13]
    • Displacement of existing prior art devices[14]
    • Industry awards[15]


Secondary indicators themselves can neither establish the existence of inventive step nor replace the inventive step assessment methodology, and the probative weight of these signposts will vary from case to case. Identifying secondary indicators of inventive step, if relevant, can potentially tip the scales in the Applicant’s favour, and assist in overcoming an inventive step rejection.



[1] Patents Act 1990 (Cth) s7(2) (‘Patents Act’).

[2] comprising: (a) any single piece of prior art information; or (b) a combination of any 2 or more pieces of prior art information that the skilled person could be reasonably expected to have combined; s7(3)

[3]Hood v Bush Pharmacy Pty Ltd (2020) FCA 1686 at [116]-[117] (‘Hood v Bush Pharmacy).

[4] IP Australia, Australian Patent Examiner’s Manual at “Tests for inventive step”

[5]  Lockwood Security Products Pty Ltd v Doric Products Pty Ltd (No 2) [2007] HCA 21; (2007) 235 ALR 202; 81 ALJR 1070 (23 May 2007) at [116].

[6] Elconnex Pty Ltd v Gerard Industries (1993) AIPC 90-984 at page 39, [337].

[7] Conor Medsystems, Inc. v The University of British Columbia (2005) FCA 1661 at [6] (‘Conor Medsystems v The University of British Columbia’).

[8] Ibid at [7].

[9] Ranbaxy Laboratories Limited v AstraZeneca AB (2013) FCA 368 at [503]-[504] (‘Ranbaxy v AstraZeneca’).

[10] Motorola Solutions v Hytera (n9)

[11] Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd (1981) HCA 12; (1981) 148 CLR 262 at [13].

[12] Conor Medsystems. v The University of British Columbia (n7) at [10].

[13] Sigma Pharmaceuticals (Australia) Pty Ltd v Wyeth (2010) FCA 1211 at [498].

[14] Australian Mud Company Pty Ltd v Globaltech Corporation Pty Ltd (2018) FCA 1839 at [485].

[15] Bradken Resources Pty Ltd v Lynx Engineering Consultants Pty Ltd (2012) FCA 944 at [125].