The revised guidance cites the leading case on the subject, the High Court's decision in Aktiebolaget Hassle v Alphapharm Pty Ltd  HCA 59, as endorsing the “Cripps question” approach to obviousness (as posed by Graham J in Olin Mathieson Chemical Corporation v Biorex Laboratories Ltd  RPC 157). The Patent Office "simplification" (and generalisation) of this question is stated as:
Would the person skilled in the art (in all the circumstances) directly be led as a matter of course to try the claimed invention in the expectation that it might well produce a solution to the problem?The Manual characterises this as the "obvious to try" approach, and provides the following example of a reasoned objection based on this approach:
“The problem relates to identifying compounds with antibacterial activity. The citation teaches that compounds of formula II will have antibacterial activity, although there are no examples confirming this prediction. In light of this disclosure, it would have been obvious to try compounds of formula II in the expectation that they would have antibacterial activity.”HAS THE PATENT OFFICE GOT IT RIGHT?
With all due respect to the custodians of the Manual, we are not at all sure that this is the law as stated in Hassle v Alphapharm. The High Court majority drew a distinction between "matters of routine" (discussed at paragraphs -) and "obvious or worthwhile to try" (discussed at paragraphs -).
Matters of Routine
The question posed by Graham J in Olin was endorsed by the majority in the context of "matters of routine", at . However, this was in the context of statements by Aiken J in Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd  HCA 12, cited at paragraphs - of Hassle:
"The test is whether the hypothetical addressee faced with the same problem 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." (emphasis added)The majority considered that what Aiken J had in mind as "routine" was revealed by his approach to evidence of actual steps taken by the patentee, which "might show that the experiments were of a routine character which the uninventive worker in the field would try as a matter of course" (emphasis added).
It is therefore clear that what is "routine", ie what the uninventive skilled worker would do as a matter of course in the performance of their job, is not the same thing as "obvious to try".
Obvious to Try
The approach of the High Court to "obvious to try" was quite different. The majority expressly identified (at ) a divergence between the UK/European law in this regard, and the treatment of obviousness by the High Court of Australia.
Instead, the court preferred the approach (at that time) of the United States federal appellate courts, where "any criterion which adopts a notion of 'obvious to try' has been rejected in a long series of decisions" (with examples, at  to ).
The difficulty with an "obvious to try" test that can be gleaned from the US cases cited by the majority in Hassle is its lack of objectivity, and susceptibility to hindsight reasoning. Much research involves a degree of trial and error, or educated guessing, and it is unreasonable to suppose that anyone would waste time and money on an endeavour without some expectation of success. Furthermore, the potential rewards of success in some cases might justify the expenditure of substantial financial resources on testing large numbers of alternatives. Finally, once a solution has been found, it might all too easily appear obvious that it would have been worthwhile to try.
The High Court clearly concluded (at ) that the US courts' reasoning in rejecting "obvious to try" should be accepted in preference to the UK/European approach. The US approach was considered closer to that adopted in Minnesota Mining and Manufacturing Co v Beiersdorf (Australia) Ltd  HCA 9 and Wellcome Foundation.
The approach of "routine steps" directs attention to what the available evidence shows to be the normal practice of persons skilled in the relevant art, ie what do skilled workers actually do, day to day, in addressing problems within their particular field? The High Court in Hassle expressly endorsed the validity of this approach to obviousness.
"Obvious to try", however, directs attention to something quite different. It requires only some appropriate level of expectation of success, regardless of whether or not the steps required in order to try a prospective solution are "routine" in the art. The "antibacterial" example in the Manual seems to us to be a case in point. It might be true that a prior art reference that provides a strong suggestion (without proof or example) that something will work would make it "obvious to try", however it does not necessarily follow that trying will be merely "a matter of routine".
We interpret the High Court in Hassle as rejecting "obvious to try" even if the prior art suggests a possible solution. Of course, a very clear suggestion might make the solution obvious (rather than merely obvious to try). Alternatively, the suggestion in the prior art may indeed direct the skilled person to follow established routine steps to reach a solution. However, we think that the Manual is incorrect to endorse "obvious to try" as a legitimate approach in its own right, and that this is not currently the law in Australia. The Patent Office used to agree with us: a prior version of Section 18.104.22.168.5 is available in the Internet Archive.
We would therefore recommend that applicants closely scrutinise any objections raised by Australian examiners based on an "obvious to try" test, according to the current guidelines.
Since the Hassle case was decided in Australia, the Supreme Court of the United States has effectively overruled the federal appellate court decisions rejecting "obvious to try". In KSR International Co. v. Teleflex Inc. (2007) 550 US 398, the Court stated (slip op. at 17):
[It is an error to conclude] that a patent claim cannot be proved obvious merely by showing that the combination of elements was obvious to try. When there is a design need or market pressure to solve a problem and there are a finite number of identified, predictable solutions, a person of ordinary skill in the art has good reason to pursue the known options within his or her technical grasp. If this leads to the anticipated success, it is likely the product not of innovation but of ordinary skill and common sense.This seems to us to be eminently sensible, but it is not the law in Australia!