To express it in brief and understandable manner the Mexican Professor a. Rosenblueth, and Norbert Wiener, the latter considered father of Cybernetics, in an article published in 1945 coined the phrase that expresses: the best model of a cat is a cat, and preferably the same cat. It is a philosophical definition of the ideal experimental model. That model or model that seeks to reproduce the more approximate, if not total, the condition to be studied, the situation that naturally occurs in intervention or effect or action etiopathogenic and changes that occur in the model study. It is an idea without practically opposed any experimental model reproduces in its entirety and common conditions that occur naturally, and this is particularly true in medicine and research in biological sciences.
However, there are models for almost all of the processes that make up an entity and that, studied or put in place of segmental way manage to provide extremely useful information for increase our knowledge. Experimental models must meet a series of requirements to be validated and provide adequate reliability as a reflection of the process to study. These conditions or requirements have been summarized into the following criteria: facial validity: referring to the ability of the model to reproduce the visible and detectable manifestations of the process or condition to study predictive validity: the effect of the intervention will be reproducible in natural condition or the individual beneficario of the results. In other words, the effects in the model are predictable in the human or the actual situation. Construct validity: is the more difficult to achieve criterion. Refers to playback on the model of the mechanisms involved in the process to study. These criteria were expressed and established by Van der Staay FJ, Arndt SS, Nordquist RE.
(Evaluation of animal models of neurobehavioral disorders.) Behav.Brain Funct. 2009 Feb 25; 5: 11) and O Dell LE, Khroyan. TV (do Rodent Models of Nicotine Reward: What do they tell us about tobacco abuse in humans?) Pharmacol Biochem Behav. 2009 Feb; 91 (4): 481-488) Wojciech Rojewski my manual medical original author and source of the article