A–not-A test is defined by ASTM International1 as:
“A–not-A test, n—a method of discrimination testing comprised of at
least two samples; at least one sample is a previously identified
sample (“A”) and at least one is a test sample. All samples are
presented blindly, and the assessor’s task is to assign the label “A” or
“not-A” to each of the samples. (2001)”
References
1 ASTM International. 2009. Standard Terminology Relating to Sensory Evaluations of Materials and Products, E253-09a. ASTM International, West Conshohocken, PA.
E253-09a 