Evaluating Students’ First time Use of STACK in Complex Numbers Practice Exercises in an Italian Upper-Secondary School

Abstract: This paper reports a pilot study on upper-secondary students’ first-time use of STACK for practice on complex numbers in an Italian school context. The study examined how novice students engaged with STACK materials adapted from first-year university-level complex numbers activities, and how their experiences shaped their perceptions of the system. Data were collected from Moodle/STACK learning analytics, student inputs, question-level performance, and a post-activity questionnaire. The analysis focused on students’ responses, perceived ease of use, perceived usefulness, and overall acceptance of the technology. The findings show that students’ first-time use of STACK was shaped by the combined demands of mathematical reasoning, symbolic input, syntax, validation, and feedback interpretation. Students using STACK are also learning how to communicate mathematics in a system-readable form. We conclude by highlighting the importance of structured onboarding, explicit syntax guidance, and carefully designed STACK materials for upper-secondary learners.