\input zb-basic \input zb-matheduc \iteman{ZMATH 2005c.00931} \itemau{Moreira Brumatti, Raquel N.; Wodewotzki, Maria L\'ucia L.} \itemti{A perspective on the conceptions of college freshmen regarding absolute value of real numbers. (Uma perspectiva das concep\c c{}\~o{}es de calouros universit\'arios sobre o valor absoluto de n\'umeros reais.)} \itemso{Bolema 17, No. 22, 63-81 (2004).} \itemab In this paper we begin with a somewhat pedagogical statement about what we think is the role of the absolute value concept in the mathematical context and we try to unders-tand how a student learns this concept. The theoretical perspective of cognitive develop-ment is an extension of Piaget's ideas about reflective abstraction and it allows one's to describe the mental constructions present in a learning process of advanced mathematical concepts. Based on a initial cognitive model of how the absolute value may be learned an attempt to interpret the interviewee's data using the Action-Process-Object-Schema (APOS) theoretical framework is made. There is evidence showing that the level of abstraction of these starting college students enable them to have an adequate unders-tanding of the absolute value. The results of the data analysis also made us consider the graphic representations and the cooperative learning as relevant factors of a pedagogical approach because they seem to lead a more efficient and meaningful knowledge. \itemrv{~} \itemcc{C35} \itemut{learning theory; cognitive constructions; undergraduate mathematical knowledge; absolute value; real numbers} \itemli{} \end