Welcome to the new version of the Patents Manual. Please note there are changes to the numbering and sequence of the chapters and pages in the manual. You are encouraged to take the time to explore and familiarise yourself with this new structure. Application of the Balance of Probabilities in Examination

Date Published

Key Legislation: 

Patents Act:

  • s18 Patentable inventions
  • s27 Notice of matters affecting validity of standard patents  
  • s40 Specifications ​​​​​​​

General Approach

All grounds of objection are raised, and maintained, on the balance of probabilities. The balance of probabilities requires examiners to weigh up all the material before them and decide, on balance, whether an objection is more likely than not to be applicable. Another way of viewing the balance of probabilities is that the objection is highly plausible, more probable than not or prima facie reasonable.

Question of fact or law

The balance of probabilities only applies to questions of fact. Therefore, examiners need to apply the balance of probabilities test in weighing up factual matters that form the basis for an objection. Factual matters which are most relevant in the context of assessing the grounds examined for a standard patent application, listed below, include:

  • novelty; s18(1)(b) – what a prior art document would disclose to a skilled person, any submissions provided by the applicant or patent attorney;
  • inventive step; s18(1)(b) – what would be a matter of routine for the skilled person at the priority date, whether there were indicators of inventive step, what is part of the common general knowledge, any submissions provided by the applicant or patent attorney;
  • clear enough and complete enough disclosure; s40(2)(a) – whether there are statements in the complete specification, prior art or any other matters on file (for example, third party re-examination requests or matter filed under section 27, submissions provided by the applicant or patent attorney) which can be used to assess whether the complete specification discloses the claimed invention in a manner which is clear enough and complete enough for the skilled person to perform the invention over the whole width of the claims;
  • support; s40(3) – whether there are statements in the complete specification or any submissions provided by the applicant or submissions on file that the claims are not broader than is justified by the extent of the description, drawings and contribution to the art;
  • manner of manufacture; s18(1)(a) – all the relevant factors to determine whether the substance of the claimed invention falls within the realm of patentable subject matter. This is a factual enquiry to arrive at a characterisation of the claimed invention (see General Principles – Assessing Manner of Manufacture) where statements in the specification are assessed in conjunction with the state of the art, for example any prior art documents, as well as submissions provided by the applicant or patent attorney; and
  • usefulness; s18(1)(c) – whether there are statements in the specification, or submissions on file, which can be used to assess whether the claimed invention achieves the promised benefit, and whether a specific, substantial and credible use of the claimed invention has been disclosed.​​​​​​​

Questions of law, such as the proper construction of a claim, and whether a claim when properly construed, defines a manner of manufacture, or novel or inventive subject matter, are not open to a balancing of probabilities or questions of doubt.  Consequently, submissions along those lines should not be accepted.  Any uncertainties in how the law is to be applied to the facts are to be resolved by the decision maker (during examination this is the examiner).

Consideration of prior use

A novelty or inventive step objection may be raised on the basis of information made publicly available through doing an act, including a prior use. Information about the use, for example, a report about the exhibiting of an invention at a machinery field day, is prima facie evidence that the invention was displayed and an objection should be raised in the first instance. However, evidence provided by the applicant as to the circumstances of the use (for example, private and in confidence) and what was disclosed by the use will need to be weighed carefully. If in doubt, examiners need to consider consulting Patent Oppositions.

Examination practice

Examiners are to determine whether an objection is prima facie reasonable at the first report stage. In response to the objection, applicants can provide submissions or evidence that shifts the balance of probabilities in their favour. The nature and relevance of the submissions and evidence needs to be considered. It is not sufficient for the applicant to merely raise doubts in the examiner’s mind; there must be a substantial doubt before an objection is withdrawn. In most cases, persuasive reasoned argument from the applicant in response would be sufficient to tip the scales in the applicant’s favour, however there may be circumstances where supporting evidence is required. For example, if a statement in the submission is improbable, substantial supporting evidence would be required to convince an examiner. Supporting evidence would not be necessary where the submission is inherently probable.

Where doubt (even substantial doubt) is raised by the applicant, examiners need to consider whether the balance could be shifted in favour of maintaining the objection by identifying further information that would support the objection. For example, evidence might be obtained that rebuts an assertion made by the applicant.

Submissions from applicants that a novelty or inventive/innovative step objection based on a foreign language document cannot be maintained on the grounds that it has not been demonstrated that an English translation of the document (machine or otherwise) was available to the public before the priority date should not be accepted. In this situation, it is reasonable for examiners to argue that in applying the balance of probabilities, the onus falls on the applicant to demonstrate that the relevant features are not disclosed in the document.

Amended Reasons

Amended Reason Date Amended

Published for testing

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