The most important thing for a scientific ghost hunter to know is the science behind what he or she is doing. Anyone who has studied physics knows how daunting it is to learn the philosophical and mathematical formulas needed to fully comprehend, express, and apply natural laws. 

Occam’s razor is a principle attributed to the 14th-century English logician and Franciscan friar William of Ockham. It forms the basis of methodological reductionism, and is also called the principle of parsimony or law of economy. In other words, given two equally predictive theories choose the simpler one, the one with fewer unnecessary assumptions. Occam's Razor has become a basic perspective for those who follow the scientific method. It is important to note that it is a heuristic argument that does not necessarily give correct answers; it is, however, an indispensable guide to choosing the scientific hypothesis which (currently) contains the least number of unproven assumptions. Often, several hypotheses are equally "simple" and Occam's Razor does not express any preference in such cases.

Sources: 

  • http://en.wikipedia.org/