Information architecture forms the foundation of users' navigation experience. Open card sorting is a widely-used method to create information architectures based on users' groupings of the content. However, little is known about the method's cross-study reliability: Does it produce consistent content groupings for similar profile participants involved in different card sort studies? This paper presents an empirical evaluation of the method's cross-study reliability. Six card sorts involving 140 participants were conducted: three open sorts for a travel website, and three for an eshop. Results showed that participants provided highly similar card sorting data for the same content. A rather high agreement of the produced navigation schemes was also found. These findings provide support for the cross-study reliability of the open card sorting method.