This paper presents a set of data generated and analyzed by the Edu4Sec Project – Effective Education for Improving Data Security Awareness. The project commenced in 2016 and is being implemented by a multidisciplinary team based at the University of Padova. The aim is to improve secondary school students’ data security awareness and develop behaviors and strategies to reduce cyber risks arising from data security issues. Three secondary schools have been involved in a quasi-experimental research design. A training intervention was provided to 116 students engaged in experiential and interactive learning activities related to key concepts of data security. The same intervention was provided to the experimental group of 140 students, supplemented by gamification elements. The paper focuses on the pre- and post-intervention questionnaire results.