Occam's Razor

• UltimaOnline

  18 Oct 08, 23:43
• Occam's Razor, that's an interesting choice of a nick.

 

 

 

FYI for all forum members and visitors, this name has tremendous depth of significance across many scientific disciplines, including it's involvement (direct or indirect) in History, Logic, Computer Science, Probability Theory & Statistics, Physics, Engineering, Chemistry, Evolutionary Biology, Medical Science ("Dr House, M.D." Season 1, Episode 3), Psychology, Religion vs Theology vs Philosophy (eg. the existence of God), etc.

 

 

 

>>> Occam's Razor - Methodological principle of parsimony in scientific explanation; A rule in science and philosophy stating that entities should not be multiplied needlessly. This rule is interpreted to mean that the simplest of two or more competing theories is preferable and that an explanation for unknown phenomena should first be attempted in terms of what is already known. A watchword for many reductionist or nominalistic philosophies. <<<
Source : http://www.answers.com/Occam's%20Razor "
 
 
>>> There are two senses in which Occam's razor can be seen at work in the history of science. One is ontological reduction by elimination and the other is by intertheoretic competition.
In the former case the following are examples of reduction by elimination: The impetus of Aristotelian Physics, the angelic motors of medieval celestial mechanics, the four humors of ancient and medieval medicine, demonic possession as an explanation of mental illness, phlogiston theory from premodern chemistry, and vital spirits of premodern biology.
 
In the latter case there are three examples from the history of science where the simpler of two competing theories each of which explains all the observed phenomena has been chosen over its ontologically bloated competitor: the Copernican heliocentric model of celestial mechanics over the Ptolemaic geocentric model, the mechanical theory of heat over the Caloric theory, and the Einsteinian theory of electromagnetism over the luminiferous aether theory. <<<
Source - http://www.answers.com/Occam's%20Razor
 
 
>>> Founder of DNA structure Francis Crick has commented on potential limitations of Occam's razor in biology. He advances the argument that because biological systems are the products of (an on-going) natural selection, the mechanisms are not necessarily optimal in an obvious sense. He cautions: "While Ockham's razor is a useful tool in the physical sciences, it can be a very dangerous implement in biology. It is thus very rash to use simplicity and elegance as a guide in biological research." <<<
Source - http://www.answers.com/Occam's%20Razor
 
 
In Medicine (see "Dr House, M.D." Season 1, Episode 3) -
>>> When discussing Occam's razor in contemporary medicine, doctors and philosophers of medicine speak of diagnostic parsimony. Diagnostic parsimony advocates that when diagnosing a given injury, ailment, illness, or disease a doctor should strive to look for the fewest possible causes that will account for all the symptoms. While diagnostic parsimony might often be beneficial, credence should also be given to the counter-argument modernly known as Hickam's dictum, which succinctly states that "patients can have as many diseases as they damn well please". It is often statistically more likely that a patient has several common diseases, rather than having a single rarer disease which explains their myriad symptoms.

 

Also, independently of statistical likelihood, some patients do in fact turn out to have multiple diseases, which by common sense nullifies the approach of insisting to explain any given collection of symptoms with one disease. These misgivings emerge from simple probability theory, which is already taken into account in many modern variations of the razor; and from the fact that the loss function is much greater in medicine than in most of general science, namely loss of a person's health and potentially life, and thus it is better to test and pursue all reasonable theories even if there is some theory that appears the most likely.

 

Diagnostic parsimony and the counter-balance it finds in Hickam's dictum have very important implications in medical practice. Any set of symptoms could be indicative of a range of possible diseases and disease combinations; though at no point is a diagnosis rejected or accepted just on the basis of one disease appearing more likely than another, the continuous flow of hypothesis formulation, testing and modification benefits greatly from estimates regarding which diseases (or sets of diseases) are relatively more likely to be responsible for a set of symptoms, given the patient's environment, habits, medical history and so on. For example, if a hypothetical patient's immediately apparent symptoms include fatigue and cirrhosis and they test negative for Hepatitis C, their doctor might formulate a working hypothesis that the cirrhosis was caused by their drinking problem, and then seek symptoms and perform tests to formulate and rule out hypotheses as to what has been causing the fatigue; but if the doctor were to further discover that the patient's breath inexplicably smells of garlic and they are suffering from pulmonary edema, they might decide to test for the relatively rare condition of Selenium poisoning.

 

Prior to effective anti-retroviral therapy for HIV it was frequently stated that the most obvious implication of Occam's razor, that of cutting down the number of postulated diseases to a minimum, does not apply to patients with AIDS - as they frequently did have multiple infectious processes going on at the same time. While the probability of multiple diseases being higher certainly reduces the degree to which this kind of analysis is useful, it does not go all the way to invalidating it altogether - even in such a patient, it would make more sense to first test a theory postulating three diseases to be the cause of the symptoms than a theory postulating seven. <<<

 

Source - http://www.answers.com/Occam's%20Razor

 

 

 

You're da Man, Mr OccamRazor Dude!
 
 
P.S.
Lastly, though there's no direct connection, I only use Razer mouse for my computer (specifically the humble Razer Krait, which I actually prefer over higher end models such as the Diamondback, Copperhead, DeathAdder, Lachesis, BoomSlang, Salmosa), together with the Razer eXactMat mouse pad complete with wrist cushion.