Development of Self-Control Instruments for Aggressive Behaviorin the Class XI Vocational School of Diponegoro Majenang

Verbal aggressive behavior is exhibited in individuals due to low self-control. This study aimed to develop instruments for aggressive behavior in students, to help improve the students' self-control. The instrument development method was used. The data were collected through a questionnaire tested on 30 students of class XI SMK Diponegoro Majenang, chosen by random sampling. The Aiken formula with valid conditions > 0.73 was used for evaluating the validity. The KMO test results of 0.728 > 0.50 meant that the instrument could be considered valid as a measuring instrument. The reliability test was carried out with the Alpha Cronbach formula and a result of 0.853 > 0.60 was obtained. This meant that the self-control scale could be considered reliable to measure the level of control in students exhibiting aggressive behavior. Keywords: development; instrument; self-control; aggressive behavio