4-Experimental design and statistical analysis
There are extensive sources of guidance on study design and statistical analysis in a separate section of this website. These, together with a statistician, should be consulted at an early stage.
Other sections of the PREPARE guidelines cover the animal and facility related issues of experimental design.
An additional critical part of "experimental design" is evaluation of the animals' housing, husbandry and care. See the section on Housing and Husbandry.
Define the experimental unit and decide upon animal numbers.