Discrimination Testing - Statistical Basis

Statistical Basis

The statistical principle behind any discrimination test should be to reject a null hypothesis (H₀) that states there is no detectable difference between two (or more) products. If there is sufficient evidence to reject H₀ in favour of the alternative hypothesis, H_A:There is a detectable difference, then a difference can be recorded. However, failure to reject H₀ should not be assumed to be sufficient evidence to accept it. H₀ is formulated on the premise that all of the assessors guessed when they made their response. The statistical test chosen should give a probability value that the result was arrived at through pure guesswork. If this probability is sufficiently low (usually below 0.05 or 5%) then H₀ can be rejected in favour of H_A.

Tests used to decide whether or not to reject H₀ include binomial, χ2 (Chi-squared), t-test etc.