Consumers tend to overestimate the likelihood as well as the frequency of purchase. To determine accurate volume predictions, you must understand the precise level of overestimation to accurately predict actual consumer behaviour. By weighing subgroups according to their presence in the population, we can extrapolate the buying intention.
From a regular taste test, we select a subsample among those consumers that have indicated they would definitely/probably buy. To find out actual purchase frequency in their home environment, respondents are given sufficient samples and are required to replace each test product they use by a product they would otherwise have bought.