This research aims to construct a measurement tool to assess the constructive criticism competence in Thai university students. The data were collected using a mixed-methods design. We conducted research with three phases: 1) construct development by interviewing 12 experts to obtain the behavioral indicators in the context studied, 2) Instrument validation to verify the validity and reliability through the pilottesting, and finally, 3) Instrument application by purposely collecting data from 335 undergraduate students from four southern Thai universities to analysis the construct validity and reliability of the instrument. For data analysis, qualitative content analysis from the interview was show with descriptive. The construct validity was analyzed based on the EFA (Exploratory Factor Analysis) and measured the instrument's reliability based on the value of Cronbach’s Alpha Coefficient. The result of the study showed that the Constructive Criticism Competence Self-Assessment Instrument (CCC-SI) has fulfilled the requirements of instrument’s validity and reliability. There are three aspects to measure constructive criticism competence included, 1) Mindful listening, with 5 items, 2) Intellectual humility with 11 items, and 3) Communication flexibility with 5 items. The implications for practice are discussed included, the instructor’s role to assist and encourage learners throughout the learning process. This is crucial to achieving the aim of future learning and encourages each student to reflect on their progress.

Constructive Criticism, Self-Assessment, Student Evaluation, Criticism characteristic, Undergraduate Student