A factorial experiment is an experiment containing every combination of the selected factor levels of
all its experimental factors. With experimental
factors having 
,
,
..., 
factor levels, a complete factorial design has
 |
distinct treatment combinations before replication. Here "complete" means that none of the selected combinations is omitted. Factorial designs permit estimation
of both main effects and interactions between experimental
factors. A 
factorial experiment has 
experimental factors,
each having two factor levels.
