This paper presents a study that examines learning styles and cultural background to reveal differences in users’ categorizations and mental models of the information architectures (IAs) in two website domains (museum and news sites) by using a card sort methodology. These informal learning domains were selected since people who visit museum websites may well be tourists coming from different cultures, and many people visit news websites almost every day, therefor people would seem to be familiar with their structure. Furthermore, these domains provide rich multimedia information for its users. To evaluate IAs of these websites, a simple, quick, cheap, and reliable method was used that is called the card sort technique. Findings of the study illustrated interesting and meaningful differences between users with different learning styles and among different cultural groups. This study also made a methodological contribution, showing that the card sort methodology could be used to show learning styles and cultural differences.