In mono-sequential tests of food products most manufacturers rely on monadic results, and not on results for consolidated samples, because they are convinced that in real-life situations people tend to consume products from one rather than two brands  on a single occasion. Hence, during one meal consumers hardly ever compare two products from the same category.

Nevertheless, in order to rely on monadic test results in each research cell we should have ‘exactly the same consumers’. This is why a lot of weight should be attached to proper sample selection. This is also why most research agencies monitor demographic variables, brand usage, category usage frequency, or frequency of consuming particular variants within the category.

EEI additionally controls the level of hunger among respondents participating in particular test cells. It goes without saying that consumers who are hungrier evaluate a given product formula more positively than those whose stomachs are filled. Not controlling this variable might bias the results of any food product test.