Design and validation of a questionnaire on teachers' uses of generative artificial intelligence

• A new instrument assesses secondary teachers’ uses of generative AI (GAI). • The questionnaire comprises 30 items across six educational dimensions. • Confirmatory factor analysis confirmed a six-factor model with good fit indices. • High internal consistency and convergent/discriminant validity were demonstrated. • The tool supports teacher training and GAI-informed educational policies. The use of generative artificial intelligence (GAI) in secondary education is transforming teaching practices and students' learning experiences. This study presents the design and validation of a questionnaire to assess the various educational uses of GAI by secondary school teachers. An initial pool of items was developed based on a comprehensive review of recent literature and validated through expert judgment. The preliminary version of the instrument was administered to a sample of 486 secondary school teachers in Spain. Confirmatory factor analyses supported a six-dimension structure: teacher management, creation of teaching materials, student assessment, student empowerment, attention to diversity, and student motivation. The questionnaire demonstrated high internal consistency and adequate convergent and discriminant validity. The results show that teachers use GAI both to optimize their professional performance and to enrich students' learning experiences. Practical implications of the instrument for teacher training, institutional decision-making, and future research directions are discussed.