The growing integration of technology into education, particularly in the STEM fields, has tended to focus on its objective advantages, ignoring its affective potential. To explore this potential, based on some principles of "Kansei/Affective Engineering," an initial analysis was conducted considering 501 interventions in a conversation among six students about a previous e-learning experience. The analysis revealed the need for personalized feedback, a self-adapted pace, and the possibility to express. Based on the identified needs, three activities ("applets" based on "dynamic reasoning" and contextualized in the movement of the Sun) were designed to explore the "affective value" of the tool through the feedback it provided. Thirteen engineering students at a Japanese university participated in the experiment and the results were analyzed considering the type ("task-focus/constructivist," "self-focus/motivational") and purpose of the feedback, as well as some indicators based on the Instructional Feedback Orientation Scale. The model constructed for each student revealed that those who attributed a higher value to feedback showed a greater relation between the purpose of the feedback received and the reaction selected ("completion"-positive, "correction"-negative). Furthermore, it was found that the proposed model can inform future designs based on the potential of the feedback to promote positive reactions.