Inaugerated in Cassis, France in 1984, the International Society for Psychophysics aims to further the study and practise of psychophysics, that is to say the measurement and the study of the measurement of psychological functions. The society also aims to further the professional development of its members through annual Fechner Day meetings. These are scientific meetings at which the society membership meets to discuss ongoing progress in the development of psychophysical methods and developments or trends within the science itself.