This webinar examines efforts to prevent further sexual offending by exploring sexual interests and arousal patterns, including psycho-physiological measures and viewing time, while raising key questions about reliability, validity, standardization, interpretation, and levels of intrusiveness. Mervyn Davies, co-founder of the LOOK Assessment, reflects on decades of work in understanding and assessing human sexuality, reviewing past assessment efforts with people convicted of sexual crimes, the importance of structured measures, the limits of current knowledge, methodological challenges in developing reliable tools, and the role of assessment in preventing violence, including sexual assault.