Abstract

Open peer commentary on the article “Constructivist Model Building: Empirical Examples From Mathematics Education” by Catherine Ulrich, Erik S. Tillema, Amy J. Hackenberg & Anderson Norton. Upshot: The target article by Ulrich et al. is a good example of constructivist research in mathematics education, and illustrates how constructivism can ground a research endeavour toward modelling students’ mathematical understandings. I propose to delve into these issues of model building and reflect on Maturana’s notion of the observer. I do this through discussing issues about the language used in the article and of data description, and of analysis of students’ mathematical activity