The halo effect is a cognitive bias where the overall judgment or perception of a person or product influences subsequent specific evaluations. It is particularly evident in surveys or qualitative studies, where the opinion of one participant, often a prominent figure, influences the responses of others. This phenomenon can be affective or cognitive, reducing the ability to discriminate between different attributes and impacting marketing analyses. In marketing, the halo effect can also manifest as a positive perception of other products from the same brand, due to the influence of a flagship product.