Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.2 9/18/84; site utai.UUCP Path: utzoo!utcsri!utai!me From: me@utai.UUCP (Daniel Simon) Newsgroups: net.ai,net.cog-eng Subject: Re: Searle, Turing, Symbols, Categories Message-ID: <2552@utai.UUCP> Date: Wed, 15-Oct-86 19:17:57 EDT Article-I.D.: utai.2552 Posted: Wed Oct 15 19:17:57 1986 Date-Received: Wed, 15-Oct-86 20:47:50 EDT References: <158@mind.UUCP> <150@cwrudg.UUCP> <160@mind.UUCP> <2495@utai.UUCP> <167@mind.UUCP> Reply-To: me@utai.UUCP (Daniel Simon) Organization: CSRI, University of Toronto Lines: 140 Summary: In article <167@mind.UUCP> harnad@mind.UUCP (Stevan Harnad) writes: > >In response to my article <160@mind.UUCP>, Daniel R. Simon asks: > >> 1) To what extent is our discernment of intelligent behaviour >> context-dependent?...Might not the robot version [of the >> turing test] lead to the...problem of testers being >> insufficiently skeptical of a machine with human appearance? >> ...Is it ever possible to trust the results of any >> instance of the test...? > >My reply to these questions is quite explicit in the papers in >question: >The turing test has two components, (i) a formal, empirical one, >and (ii) an informal, intuitive one. The formal empirical component (i) >is the requirement that the system being tested be able to generate human >performance (be it robotic or linguistic). That's the nontrivial >burden that will occupy theorists for at least decades to come, as we >converge on (what I've called) the "total" turing test -- a model that >exhibits all of our robotic and lingistic capacities. By "nontrivial burden", do you mean the task of defining objective criteria by which to characterize "human performance"? If so, you are after the same thing as I am, but I fail to see what this has to do with the Turing test as originally conceived, which involved measuring up AI systems against observers' impressions, rather than against objective standards. Apparently, you're not really defending the Turing test at all, but rather something quite different. Moreover, you haven't said anything concrete about what this test might look like. On what foundation could such a set of defining characteristics for "human performance" be based? Would it define those attributes common to all human beings? Most human beings? At least one human being? How would we decide by what criteria to include observable attributes in our set of "human" ones? How could such attributes be described? Is such a set of descriptions even feasible? If not, doesn't it call into question the validity of seeking to model what cannot be objectively characterized? And if such a set of describable attributes is feasible, isn't it an indispensable prerequisite for the building of a working Turing-test-passing model? Please forgive my impertinent questions, but I haven't read your articles, and I'm not exactly clear about what this "total" Turing test entails. >The informal, >intuitive component (ii) is that the system in question must perform in a >way that is indistinguishable from the performance of a person, as >judged by a person. > >Now the only reply I have for the sceptic about (ii) is >that he should remember that he has nothing MORE than that to go on in >the case of any other mind than his own. In other words, there is no >rational reason for being more sceptical about robots' minds (if we >can't tell their performance apart from that of people) than about >(other) peoples' minds. The turing test is ALREADY the informal way we >contend with the "other-minds" problem [i.e., how can you be sure >anyone else but you has a mind, rather than merely acting AS IF it had >a mind?], so why should we demand more in the case of robots? ... > I'm afraid I must disagree. I believe that people in general dodge the "other minds" problem simply by accepting as a convention that human beings are by definition intelligent. For example, we use terms such as "autistic", "catatonic", and even "sleeping" to describe people whose behaviour would in most cases almost certainly be described as unintelligent if exhibited by a robot. Such people are never described as "unintelligent" in the sense of the word that we would use to describe a robot who showed the exact same behaviour patterns. Rather, we imply by using these terms that the people being described are human, and therefore *would* be behaving intelligently, but for (insert neurophysiological/psychological explanation here). This implicit axiomatic attribution of intelligence to humans helps us to avoid not only the "other minds" problem, but also the problem of assessing intelligence despite the effect of what I previously referred to loosely as the "context" of our observations. In short, we do not really use the Turing test on each other, because we are all well acquainted with how easily we can be fooled by contextual traps. Instead, we automatically associate intelligence with human beings, thereby making our intuitive judgment even less useful to the AI researcher working with computers or robots. >As to "context," as I argue in the paper, the only one that is >ultimately defensible is the "total" turing test, since there is no >evidence at all that either capacities or contexts are modular. The >degrees of freedom of a successful total-turing model are then reduced >to the usual underdetermination of scientific theory by data. (It's always >possible to carp at a physicist that his theoretic model of the >universe "is turing-indistinguishable from the real one, but how can >you be sure it's `really true' of the world?") > Wait a minute--You're back to component (i). What you seem to be saying is that the informal component (component (ii)) has no validity at all apart from the "context" of having passed component (i). The obvious conclusion is that component (ii) is superfluous; any system that passes the "total Turing test" exhibits "human behaviour", and hence must by definition be indistinguishable from a human to another human. >> 2) Assuming that some "neutral" context can be found... >> what does passing (or failing) the Turing test really mean? > >It means you've successfully modelled the objective observables under >investigation. No empirical science can offer more. And the only >"neutral" context is the total turing test (which, like all inductive >contexts, always has an open end, namely, the everpresent possibility >that things could turn out differently tomorrow -- philosophers call >this "inductive risk," and all empirical inquiry is vulnerable to it). > Again, you have all but admitted that the "total" Turing test you have described has nothing to do with the Turing test at all--it is a set of "objective observables" which can be verified through scientific examination. The thoughtful examiner and "comparison human" have been replaced with controlled scientific experiments and quantifiable results. What kinds of experiments? What kinds of results? WHAT DOES THE "TOTAL TURING TEST" LOOK LIKE? >> 3) ...are there more appropriate means by which we >> could evaluate the human-like or intelligent properties of an AI >> system? ...is it possible to formulate the qualities that >> constitute intelligence in a manner which is more intuitively >> satisfying than the standard AI stuff about reasoning, but still >> more rigorous than the Turing test? > >I don't think there's anything more rigorous than the total turing >test since, when formulated in the suitably generalized way I >describe, it can be seen to be identical to the empirical criterion for >all of the objective sciences... One question you haven't addressed is the relationship between intelligence and "human performance". Are the two synonymous? If so, why bother to make artificial humans when making natural ones is so much easier (not to mention more fun)? And if not, how does your "total Turing test" relate to the discernment of intelligence, as opposed to human-like behaviour? I know, I know. I ask a lot of questions. Call me nosy. > > >Stevan Harnad >princeton!mind!harnad Daniel R. Simon "We gotta install database systems Custom software delivery We gotta move them accounting programs We gotta port them all to PC's...."