- From: Jason White <jasonw@ariel.ucs.unimelb.edu.au>
- Date: Sat, 7 Aug 1999 15:29:35 +1000 (EST)
- To: Web Content Accessibility Guidelines <w3c-wai-gl@w3.org>
The one phrase in Charles' contribution to which I take exception is "non-text equivalents". As Gregg has persuasively argued on several occasions, it is not feasible to propose the inclusion of "non-text equivalents" of textual content, except in cases where the concepts being conveyed are sufficiently simple and every-day to permit a clear and widely recognisable visual representation. One needs to think, rather, in terms of visual supplements that clarify the meaning of textual material, for example in the manner that a chart or graph can be used to summarise a data table, or in which an image can identify the subject of a newspaper article, or in which layout can convey the structure of a document. The central misconception inherent in the expression "non-text equivalent" is the implication that it is possible to represent complex concepts non-linguistically--that is to say, without having ultimate recourse to language. It should also be remembered that there are fields of knowledge which are not amenable to visual (or more generally, non-linguistic) depiction. To take an extreme example, it has been argued that one of the principal reasons for introducing rigorous proofs into mathematical analysis during the nineteenth century was precisely the impossibility of constructing graphs that could represent the functions then under consideration. Hence, "geometric intuitions" could no longer serve as an adequate basis of mathematical reasoning in the calculus. Other fields, in linguistics, philosophy and the social sciences could readily be cited to show that there are contexts in which visual aids, even if not entirely infeasible, would fail completely to convey the meaning of the text and could not therefore be characterised as equivalent thereto. Of course, the same observation holds true in respect of certain auditory and visual presentations (for example, visual art and music, respectively); however it remains possible to explain the over-all effect, purpose or style of the artwork to a person who possesses the requisite vocabulary and concepts, through a description, which, however, can not do justice to the complexity and uniqueness of the artistic production itself. My argument is simply that attempting to convey complex thoughts non-linguistically is an even more problematic undertaking and generally assumes the prior acquisition, on the part of the recipient, of concepts which can only be developed in and through language. The more complex and specialised the discipline, the more obvious this problem becomes.
Received on Saturday, 7 August 1999 01:29:46 UTC