Block-Based Programming for Educational Robotics in Lower Secondary Education: An Exploratory Challenge-Based Learning Study

Time-limited robotics assessments can misrepresent classroom performance when unfinished attempts are discarded or recorded as exact completion times. This exploratory study addresses a practical reporting need: describing immediate execution and post-task perceptions while retaining non-completion, rather than ranking educational technologies. Thirty-five novice lower-secondary students participated in an approximately 80 min challenge-based implementation in three intact cohorts (n=16, 11, and 8). A structured observation record and stopwatch captured completion of a movement-and-sensor task within 10 min; a six-item questionnaire captured task-specific perceptions. Completion proportions were 16/16, 11/11, and 5/8. Kaplan–Meier estimates and restricted mean time through 10 min yielded 3.05, 4.37, and 7.85 min, respectively. In the cohort with three unfinished attempts, the completer-only mean was 6.56 min, whereas the whole-cohort restricted mean was 7.85 min; these summaries address different questions. A compact exploratory analysis of all six survey items found no Holm-adjusted p<0.05. The main finding is that short challenge-based robotics activities are feasible and engaging, but performance differences cannot be attributed to the programming platform alone.