A number of choice experiment (CE) studies have shown that survey respondents employ heuristics such as attribute non‐attendance (ANA) while evaluating food products. This paper addresses a set of related methodological questions using empirical consumer data from a CE on poultry meat with sustainability labels. First, it assesses whether there are differences in terms of marginal willingness to pay estimates between the two most common ways of collecting stated ANA (serial and choice task level). Second, it validates the self‐reported ANA behaviour across both approaches. Third, it explores the concordance of stated methods with that of the inferred method. Results show that WTP estimates from serial‐level data differ from those from choice task‐level data. Also, self‐reported measures on choice task ANA are found to be more congruent with model estimates than those for serial ANA, as well as with inferred ANA.