The main lecture today at YESS-4 is held by Laurinda Brown. The theme of her main paper is: “Observing systems – how do we see what we see?”. She aims at discussing issues concerning observations, and she points at the necessity of including discussions of theoretical, methodological and philosophical issues.

For more information, you should read her CERME-4 article and an article from Educational Studies in Mathematics. Both are published on the YESS-4 website.