Factorial experiment

In the statistical design of experiments is meant by a complete test plan (English: full factorial design) a test plan that takes all possible factor combinations.

If in an experiment, for example, are examined, each of which shall be set to two different stages in the trial of four factors, requires a complete test plan a total of 24 = 16 test runs.

The disadvantage of complete test plans is that with increasing number of experimental factors increases the number of test runs very quickly. The examination of six factors for example, would require 26 = 64 test runs. For this reason, factors of interest for reasons of economy is often avoided to some factor map in a larger number, so long as it can be assumed that interaction can be ignored.