The PCT guidelines provide useful guidance for determining when to cease a search (see also 1.1.2.4 Extent of Search and 1.1.11.10 Ending the Search). The same guidance can be applied to National phase searching:

“Reasons of economy dictate that the examiner use appropriate judgement to end the search when the probability of discovering further relevant prior art becomes very low in relation to the effort needed. The international search may also be stopped when documents have been found clearly demonstrating lack of novelty in the entire subject matter to which the claims are directed, apart from features the application of which would not involve an inventive step and which are instantly and unquestionably demonstrable as being well known in the field under consideration such that documentary evidence seems to be unnecessary. Accordingly, the examiner should not stop the search if lack of novelty is demonstrated for only a limited number of claimed embodiments, even though this would lead to an objection of lack of novelty in the written opinion.” (PCT/GL/ISPE/4 at paragraph 15.61)

Thus, the identification of a single document that addresses the novelty and/or inventive step of all the claims is not necessarily a trigger for cessation of the search. For example, if the claim is broader than the inventive concept, or there are technical features relating to the inventive concept described in the description that have not been claimed, then the examiner should consider whether they need to find further prior art in the event of possible amendment.

After doing a few searches it is quite common to be left with claims that might at first be considered novel and/or inventive – that is the purpose of course for applicants to invent new things! But don’t automatically stop there. Carefully consider whether these claims are genuinely novel and inventive. This could include considering if the feature is CGK or perhaps a feature in a different but analogous field. As your original search is likely to have been directed to the applicant’s inventive concept you should now consider an inventive step search so that you have confidence these claims are truly inventive. You should reconvene your three-person team as they can provide advice on your inventive step search.

If there are independent claims that you do not have citations for (only A docs identified) then re-convene your 3PT to confirm you have explored all reasonable approaches to searching the claimed invention. If not better art has been discovered after exploring all reasonable options, then it is time to discontinue the search. The documents that you do cite should be closest prior art and/or representative of the general state of the art.

Also, as outlined in ‘Objectives of the Search’, a purpose of a search is to discover as much of the relevant prior art as our facilities permit for the benefit of the applicant, not just for the purpose of drafting novelty or inventive step objections. From a customer service point of view, the examiner should consider the benefit of providing the applicant with a comprehensive collection of relevant citations.

An example of when this approach may be appropriate is when there are no citations addressing the inventive concept, however the breadth of the claims necessitates raising novelty citations that are unrelated to the inventive concept. In such as case, citing the closest (‘A’ level) prior art documents outlining the state of the art relating to the inventive concept may benefit Applicant in further decision making and also improve third party perceptions of IP Australia’s search quality.

There is, however, no “magic number” of citations. Examiners should exercise their professional judgement when determining which documents to cite.