Factorial surveys are a common method for studying social norms, attitudes, and hypothetical decision situations in the social sciences. Although they are usually applied in interview settings which allow for a visual representation of the factorial survey, they are also regularly used in computer assisted telephone interviews (CATI). However, we know little about the applicability of a factorial survey in an interview mode that does not allow for a visual presentation of the factorial survey. This paper investigates potential problems that may arise in implementing a factorial survey in a CATI by investigating how respondents of different age and educational backgrounds deal with factorial surveys of different degrees of complexity. To asses potential problems we rely on respondents’ self-reported response difficulties, a measure of response latency, and response consistency. We do not find that older respondents are experiencing or reporting more difficulties in processing the factorial survey. Respondents with higher levels education appear to produce more consistent responses.