Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site eosp1.UUCP Path: utzoo!watmath!clyde!burl!ulysses!allegra!princeton!eosp1!robison From: robison@eosp1.UUCP (Tobias D. Robison) Newsgroups: net.ai Subject: Re: Diagnosing strategies for humans? Message-ID: <1180@eosp1.UUCP> Date: Tue, 16-Oct-84 18:20:09 EDT Article-I.D.: eosp1.1180 Posted: Tue Oct 16 18:20:09 1984 Date-Received: Wed, 17-Oct-84 06:35:03 EDT References: <1339@pucc-h> Reply-To: robison@eosp1.UUCP (Tobias D. Robison) Organization: Exxon Office Systems, Princeton Lines: 55 I cannot suggest references, as requested, but would like to comment on the interesting fact that most doctors use strategies of deduction that are not followed in most sciences, businesses, or professions. [I'm not a doctor, just a consumer of medical services. If anyone feels I have misrepresneted an honorable profession, please feel free to comment...] Most doctors tend to diagnose as follows: They will consider some, but usually not all of the symptoms and other diagnostic data that are available to them. They will then deduce the most common diagnosis that fits most of the information considered. ("Common" is used in the sense of "occurring most often".) If this diagnosis fails as a working hypothesis, the process will be repeated. Usually at this point more diagnostic data is available, or is collected. Once again, the most common diagnosis to fit the data considered is obtained (usually excluding the diagnosis that was rejected). There is an important exception to this procedure, in that priority will be given to testing for some well-known possibilities that require speedy treatment. Interesting points about this procedure: - trying to decide what is relevant diagnostic data is itself an iterative procedure. I think there is no recognized minimum set of indications that EVERY doctor will use; I've seen diagnoses made on the basis of hardly any data at all. A practical consideration here is cost. Any reasponable comprehenive set of data would be too expensive to diagnose a common cold. - diagnoses need not fit all of the available data. Many symptoms reported by people are subjective, and many medical conditions can be present with a great variety of symptoms. Most people who do professional deducing would be more likely than doctors to rule a possibility out or in on the basis of a clear, incompatible symptom. - This reasoning procedure has a high success rate because: + it detects the most common disorders routinely. + most medical conditions can still be treated even if they are only detected after several mis-diagnoses. This reasoning process is quite unsettling to anyone who is used to doing decuctive reasoning in his or her work, and who also has an unusual medical problem. Such people will wait impatiently for their doctors to collect a comprehensive set of data and then select the matching condition, while the doctors are actually testing a sequence of progressively less likely hypotheses. - Toby Robison (not Robinson!) allegra!eosp1!robison or: decvax!ittvax!eosp1!robison or (emergency): princeton!eosp1!robison