Abstract: A device for monitoring subject compliance comprising an instrumented paper diary for subjects to record clinical trial data. The instrumented paper diary creates an objective record of the use of the diary to verify subject entries, allowing researchers and clinicians to systematically track the use of the diary in the field. Subjects record clinical trial data in a paper diary. Electronic instrumentation connected to the paper diary allows use of the diary (e.g. when it was opened and closed) to be unobtrusively tracked, recorded and evaluated against how research protocols dictate the diary to be used. The instrumented paper diary creates an objective electronic record of when the diary was being opened/closed or written upon, allowing researchers to confirm whether the date and time written on diary entries correspond to reported diary use.