Case: Harrington-Smith on behalf of the Wongatha People v State of Western Australia (No 2) (2003) FCA 893
Outcome: discussed
The relevant provisions of the Evidence Act have been analysed in cases such as Daniel v State of Western Australia (2000) 178 ALR 542, Neowarra and in Harrington-Smith on behalf of the Wongatha People v State of Western Australia (No 2) (2003) FCA 893 ( Harrington-Smith ). I respectfully adopt those analyses. It is therefore necessary to refer only briefly to its provisions. 455 In Harrington-Smith Lindgren J outlined at [20] what must be shown to establish the admissibility of evidence of expert opinion: '(a) that the opinion is relevant (including that the field of knowledge is one in which expert opinion can properly be called (see Cross on Evidence (Australian ed) at [29050]) ( Evidence Act ss 55 , 56 ); (b) that the person put forward as an expert possesses specialised knowledge in that field ( Evidence Act s 79 ); (d) that the specialised knowledge is based on the person's training, study or experience ( Evidence Act s 79 );and (e) that the particular opinion tendered is based on the specialised knowledge ( Evidence Act s 79 ).' 462 In both Harrington-Smith and in Jango , the expert anthropology reports were criticised, inter alia, on the basis that they did not 'distinguish between the facts upon which opinions [were] presumably based and the opinions themselves.' 467 I share with Lindgren J the view, as he expressed in Harrington-Smith at [26] that there are 'great practical differences' between experts reports from different disciplines. His Honour said that 'Admittedly, there are great practical differences in the present respect between, for example, Makita , an appeal concerned with a report of expert opinion given by a "physicist who specialised in the investigation of slipping accidents" ... in relation to the slipperiness of a stair, and a case such as the present one, concerned with reports of opinions given by historians and anthropologists in relation to the more complex question whether there are communal, group or individual rights and interests of Aboriginal peoples in relation to land or waters, where the rights and interests are possessed under the traditional laws acknowledged, and the traditional customs observed, by the Aboriginal peoples, and they, by those laws and customs, have a connection with the land or waters...' 468 Underlying his Honour's statement is the notion that science and mathematics are exact disciplines, whereas the disciplines of anthropology, humanity, much of economics, and history are not. There is a longer list which could be created. In most if not all disciplines, opinion is formed by reasoning drawn from a group of 'facts'. The facts may be drawn from a scientific experiment, historical documents or a series of conversations held with members of a native title claimant group. However, 'facts' themselves have varying degrees of primacy or subjectiveness. Some facts are now, in reality (and despite the deconstructionists) incontrovertible. Our communication systems make them so: the use of numbers in measurement is a clear example. Some are obviously more subjectively perceived: estimates, descriptions of persons or events, and the like (the explanations of Dr Wells for the significance she attributed to many contemporary records provides examples). Some are complex and themselves involve judgment. In the realm of expert evidence, the primary data upon which an opinion is based may comprise a mixture of primary and more complex facts. The opinion may then be further based upon an interpretation (sometimes requiring expertise) of those facts and that stage may require an exercise of judgment, sometimes fine judgment, by the person concerned. 469 This is not the occasion to dilate at length upon such matters. That is better left to others. The important thing in any expert's report, in my view, is that the intellectual processes of the expert can be readily exposed. That involves identifying in a transparent way what are the primary facts assumed or understood. It also involves making the process of reasoning transparent, and where there are premises upon which the reasoning depends, identifying them. An understanding of the nature of the judicial process in addressing expert evidence would readily recognise the need for the expert's report to communicate those matters to the court. 470 The premises, whether based on primary facts or on other material, then need to be established. Their ready identification ensures that the means of satisfaction whether by proof of primary facts or in some other way can be addressed by the party relying upon that expert opinion, generally by the legal representations.