It's common for businesses to rely on self-reported survey respondents—people who claim they've made certain purchases in the past—when conducting market research. However, that approach may lead to flawed data and incorrect conclusions.

That's according to a recent comparison of different sampling methodologies conducted by 84.51° Media.

An infographic (below) covers key findings from the study.

It looks at the quality of survey results for self-reported respondents compared with behaviorally-verified respondents (those whose purchases have been confirmed with transaction data).