International Journal of Advanced Science and Technology Vol. 29, No.4, (2020), pp. 3055 – 3068 3055 ISSN: 2005-4238 IJAST Copyright ⓒ 2020 SERSC Mapping the Threat of Radicalism Symptoms among Upper-Secondary Students: A Mix Methode Approach Shaleh Shaleh 1* , Zamroni Zamroni 2 , Mukminan Mukminan 3 , Ashadi Ashadi 4 Ajat Sudrajat 5 , Supaat Supaat 6 , Mifedwil Jandra 7 , Syahrul Ramadhan 8 1 Doctoral Program of Education Research and Evaluation, Post-Graduate Program, Yogyakarta State University, and State Islamic University of Sunan Kalijaga Yogyakarta, Sleman, 55281, Indonesia 2 Prof, Post-Graduate Program, Yogyakarta State University, Sleman, 55281, Indonesia 3 Prof, Post-Graduate Program, Yogyakarta State University, Sleman, 55281, Indonesia 4 Prof, Post-Graduate Program, Yogyakarta State University, Sleman, 55281, Indonesia 5 Ph.D, Post-Graduate Program, Yogyakarta State University, Sleman, 55281, Indonesia 6 Dr, Islamic State Institute of Kudus, 59322, Indonesia 7 Prof, Ahmad Dahlan University, Yogyakarta, 55166, Indonesia 8 Education Research and Evaluation, Post-Graduate Program, Yogyakarta State University, and State *Corresponding Author: shalehmaruf.413@gmail.com Abstract This study aims to explore the threat of radicalism by mapping the elements constructing its symptoms from a study that examines their strength among high school students in a Special Province in Indonesia. For this purpose, a sequential exploratory mix method design was employed in two stages of research. In the first stage, qualitative research was conducted with a case study design to find indicators of the symptoms of radicalism and its aspects, which were used in the subsequent development of quantitative survey research instruments in stage II. The second stage involved 1000 respondents of upper-secondary student eleventh-graders selected through a proportioned cluster random sampling technique. The results revealed that the construct of radicalism symptoms among upper-secondary students has five features of attitude, namely: intolerance, fanaticism, literality, pessimism, and revolution. Based on the mapping of this research, elements of textual and revolutionary attitudes have a stronger tendency compared to the other three aspects. The textuality was related to the approach to understanding jihad and Khilafah literally. At the same time, the aspect of revolutionary attitude contained a tendency to approve the efforts to change the existing order and convention with Islamic laws as a whole in the life of society and the state. Keywords Radicalism Symptom, Upper-Secondary Students, Intolerance, Islamic Education Sciences