Animal research in psychiatry suffers from a poor translational value. It is the same for all other disciplines. Our purpose in this chapter is therefore to highlight all the parameters that can lead to a non-reproducibility of interlaboratory experiments as well as intralaboratory. This is to point out the experimental parameters that are likely to lead to bias. Parameters are essentially: breeding conditions, animal strains, housing, handling, illumination, weather conditions, age, and the actual experimental conditions. Controlling these parameters is not enough if there is no consensus of the scientific community to implement them in a standardized way. However, it is possible to improve the translational concept by taking stock of what has been operational without forgetting to standardize as much as possible the essential parameters of behavioral research. Now there are calls to take a different approach to animal experimentation, by asking not what was controlled in an experiment, but what was ignored. This new school of thinking has been termed "therioepistemology"; the study of how knowledge is gained from animal research. The focus is on what's been ignored in an animal data set, why it's been ignored, and how it affects the model or experiment.
Keywords: Age; Breeding; Experimental parameters; Handling; Housing; Illumination; Reproducibility; Strains; Therioepistemology.