Thisbook constitutes the refereed proceedings of the 18th International Conferenceon Computer Assisted Assessment, CAA 2015, held in Zeist, The Netherlands, inJune 2015. The 15 revised full papers presented were carefully reviewed andselected from numerous submissions. The papers present current developments intechnology-enhanced assessment. Topics covered include: automatic item generation, computeradapted testing, the use of multimedia in assessment, e-assessment policies.