In this paper we present a corpus of interactions of older and younger users with nine different dialogue systems. The corpus has been fully transcribed and annotated with dialogue acts and “Information State Update” (ISU) representations of dialogue context. Users not only underwent a comprehensive battery of cognitive assessments, but they also rated the usability of each dialogue system on a standardised questionnaire. In this paper, we discuss the corpus collection and outline the semi-automatic methods we used for discourse-level annotations. We expect that the corpus will provide a key resource for modelling older people’s interaction with spoken dialogue systems.