The boom in online marketing research represents one of the fastest-growing segments of the research industry. Although the design and quality of online surveys has received widespread attention, little empirical research compares the effectiveness of online and offline qualitative research techniques. Therefore, this research compares offline focus groups, online focus groups and e-Delphi with respect to depth, breadth, efficiency, group dynamics, non-verbal impressions and attitudes of respondents. Results show that offline focus group results have the highest depth and breadth, and are most efficient, leading to high-quality outcomes. However, e-Delphi discussions provide very elaborate and relatively deep outcomes that give a good impression of respondents' feelings and attitudes. Results from online focus groups remain rather superficial, but experts value the spontaneous reactions and interactiveness, and consider online focus groups very efficient.
Brüggen, E. C., & Willems, P. (2009). A Critical Comparison of Offline Focus Groups, Online Focus Groups and E-Delphi. International Journal of Market Research, 51(3), 363-381. https://doi.org/10.2501/S1470785309200608