Definition:
“The smallest division of the experimental material such that any two experimental units can receive different treatments”.
It is the unit of randomisation and of statistical analysis when comparing groups
In this study the animals are all housed in one cage and the treatment is given by injection.
Any two animals can receive different treatments, so the animal is the experimental unit and “N” (the total number of subjects) is 8
In this study the animals are housed two per cage and the treatment is given in the food or water.
What do you think is “N”, the total number of experimental units in this case?
