Critical importance of common general knowledge in Australian patent law

Managing IP is part of Legal Benchmarking Limited, 1-2 Paris Gardens, London, SE1 8ND

Copyright © Legal Benchmarking Limited and its affiliated companies 2025

Accessibility | Terms of Use | Privacy Policy | Modern Slavery Statement

Critical importance of common general knowledge in Australian patent law

Sponsored by

fbrice-400px.png
sydney-3605032.jpg

Jacqueline Warner and Marcus Caulfield of FB Rice explain the significance of common general knowledge (CGK) in the patentability of inventions in Australia and the evidentiary processes that are adopted as a result

What is CGK?

Australian courts have indicated that CGK is the technical background knowledge and experience that is available to the hypothetical skilled worker in a particular field. It is accepted without question by the majority of those skilled workers and becomes part of their common stock of knowledge.

CGK is not restricted to information that may be memorised and retained. It also includes material that is known to exist and would be referred to routinely by the skilled worker even if the skilled worker is not consciously aware of the information.

CGK may include information available globally in standard textbooks, handbooks, dictionaries, industry magazines in the field and prior art acknowledged in patent specifications. CGK does not necessarily extend to information that is widely read or circulated to the skilled person or to information found by conducting searches.

Inventive step determination

The Patents Act 1990 prescribes that an invention is taken to involve an inventive step unless it would have been obvious to a person skilled in the relevant art (PSA) in light of the CGK, as it existed before the priority date, alone or in combination with the relevant prior art. Accordingly, CGK is the threshold issue to be addressed in an inventive step assessment.

Evidentiary approaches to proving CGK

Determining CGK is a factual test conducted with the aid of a person skilled in the art. What constitutes CGK can only be established by evidence. The evidentiary approaches to proving CGK vary depending on whether the CGK is being considered before IP Australia (IPA) or the courts.

During prosecution of a patent application before IPA, an assessment of inventive step involves the examiner formulating an opinion of what constitutes CGK based on material such as textbooks, dictionaries, magazines and patent specifications. Examiners consider arguments against CGK on merit and apply balance of probabilities considerations.

During opposition proceedings before IPA, CGK is established through written declaratory evidence from an expert in the field of the invention. Although the rules of evidence do not apply, the commissioner will evaluate the evidence, with hearsay evidence given less weight than first-hand testimonies and non-expert evidence.

Before Australian courts, the Evidence Act 1995 allows the admissibility of evidence in the form of expert opinions. An expert’s opinion may be admitted if the expert has “specialised knowledge” based on training, study or experience, provided the evidence is “wholly or substantially” based on that expert knowledge.

The courts will consider expert evidence from each side concurrently to establish the CGK. This is an effective way for judges to understand the technical complexities of a case. It can, however, be difficult to establish the CGK to meet the requisite evidentiary burden.

CGK failures

In Arrow Pharmaceuticals v Novartis [2019] APO 22, the delegate found that CGK did not extend to information included in a textbook published 17 days before the priority date of the opposed application on the basis that there was not enough time for the information to be generally accepted and assimilated by those skilled in the art. It had not become part of their “common stock of knowledge”.

In Aktiebolaget Hassle and Astra Pharmaceuticals v Alphapharm [2000] FCA 1303, the Full Federal Court noted that CGK did not equate to information that might be found by a diligent searcher and mere public availability is not sufficient to establish CGK.

CGK successes

In Minnesota Mining & Manufacturing v Beiersdorf (Australia) (1980) 144 CLR 253, the High Court held that the claimed invention was obvious in light of the CGK alone.

In Merial v Intervet International (No 3) [2017] FCA 21, the Federal Court considered concurrent evidence from experts and utilised the joint expert reports to identify the CGK.

Steps to establish CGK

The following steps should be adhered to in establishing CGK:

  • Choose an independent credible expert with a strong command of the technical field of the invention;

  • Ensure that the expert understands that their role is to assist the court, not be an advocate for either party;

  • The testimony should be written in the expert’s words and avoid legalese; and

  • The testimony should be substantiated by reference materials publicly available well before the priority date.

The CGK in a technical field is integral in assessing the patentability of an invention in Australia. It is therefore critically important that it is correctly determined. This may be challenging, as the state of the CGK is based on evidence that itself must be assessed for its suitability in representing what would have been known to the skilled person at the relevant time.

more from across site and SHARED ros bottom lb

More from across our site

AI
Leaders at four firms share their hiring approach, including whether AI knowledge is a must-have for new staff
McKool Smith and Licks Attorneys are acting in the dispute, which alleges infringement of patents covering video-related technologies
Legacy firm Allen & Overy agreed a high-profile tie-up with US firm Shearman & Sterling in May last year
News of Verizon settling its lawsuit with Headwater Research and a copyright setback for AI firm Perplexity at a New York court were also among the top talking points
IPH, which owns several IP businesses in the APAC and Canada, reported a 16.5% increase in revenue and 13% jump in profit after tax
With Ireland’s government re-engaging with the idea of a UPC referendum, it provides a chance to improve the system further
US-based company says appointment of Jorge Ordonez shows its momentum as a private-equity-backed platform expanding in the IP services market
The firm hired an IP litigation team during the reporting period and has entered the Managing IP rankings for trademark work
Masaki Mikami of Marks IP explains how he helped prove acquired distinctiveness to secure protection for 'Pocky' in Japan
Daralyn Durie discusses the ‘amazing’ opportunity of working on an AI case, the value of celebrating women, and how to build the next wave of talent
Gift this article