Occam’s razor rule

Eisner, D. A., and Trafford, A. W. (2002). Heart Failure and the Ryanodine Receptor Does Occam s Razor Rule Circ Res 91(11) 979-81. 

Many effects of iodide on thyroid cell metabolism have been reported in various thyroid models of various species with various kinetics. To simplify the analysis, we shall consider the results mainly obtained on human thyroid material under conditions in which iodide oxidation and binding to organic molecules occurs. Moreover, we shall apply the Occam s razor rule i.e., consider the minimum number of mechanisms necessary to explain all findings. Our scheme, therefore, may not involve other mechanisms still to be demonstrated. 

It should be mentioned here that the Occam s razor rule has been mentioned from time to time by those who continue to object to the apparent explosion of topological indices, which has occurred in more recent years in QSAR, but the simplest of competing theories being preferred does not extend to replacing theories with descriptors. Therefore, the simplest of competing descriptors should not necessarily be preferred. What is important for molecular descriptors is not how similar they are and how much they may duplicate one another, but do they differ one from another in some details that are important (for the structure-property-activity relationship). 

Many stereochemical results like these, and the consistent observation of nonthermodynamic products that would not be expected from two-step mechanisms, have accumulated to support the operation of the pericyclic mechanism in most cases. Recent advances in experimental and theoretical techniques have allowed chemists to probe the mechanisms of pericyclic reactions at time scales far shorter than the time required to rotate about a C—C cr bond, and these experiments have supported concerted mechanisms for some pericyclic reactions and nonconcerted mechanisms for others. In practical terms, though, if no experimental or theoretical evidence rules it out, Occam s razor compels one to propose a concerted mechanism in favor of a nonconcerted one. 

None of these has been ruled out rigorously in every case. However, a pathway Xa or Xb may best satisfy Occam s Razor. 

In addition, as discussed, RST provides a rigorous framework for eliminating superfluous condition attributes that provide irrelevant information. This leads to a simplification of the rules since the number of condition attributes is significantly reduced, a feature of the RST method that accords well with the principle of Occam s razor [24]. 

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