<p>Research on generalization in elementary school is a key topic in mathematics education. This study analyzes the generalization processes among fourth-grade students (9–10&#xa0;years old) while working with functional relationships, focusing on the interplay between generalizations, justifications, and mediations during a lesson. Specifically, we identify and characterize the generalizations and justifications made by 22 students and describe the mediations carried out by the teacher-researcher throughout the class. Additionally, we examine the relationships between the levels of generalization, justifications, and mediations. Our findings reveal that students demonstrated varying levels of sophistication in their generalizations, which were consistently supported by justifications and mediations. Justifications played a crucial role in validating and explaining the students’ generalizations, while mediations facilitated their engagement with the task and supported the generalization process throughout the lesson. We conclude that justification and mediation are integral components of the generalization process, emphasizing its active and social nature. Our study underscores the importance of fostering classroom discussions and encouraging students to articulate their reasoning and conjectures, promoting deeper understanding and collaborative learning.</p>