In this Special Interest Group (SIG) the attendees will discuss methods for capturing usability data over time. Specifically, we will share industry best practices, brainstorm alternative solutions, as well as compare and contrast usability engineering methods for capturing usability problems that persist over time. We will also explore why longitudinal research is not a more common UCD practice. Keywords Usability engineering, longitudinal data, user performance ACM Classification Keywords H5.m. Information interfaces and presentation (e.g., HCI): Miscellaneous.