This paper analyses the conceptualization of time dilation among Uruguayan secondary school students, using a constructivist teaching sequence to teach the Special Theory of Relativity (STR) in four physics courses. The framework of Vergnaud's Conceptual Field Theory is adopted, and a qualitative-interpretative methodology is used to identify operational invariants at four moments of each class based on the students' written, oral, gestural, and pictorial records. The results show that the situation considered is appropriate for conceptualizing time dilation
(Uruguay) et al. (Mon,) studied this question.