Vol. 26 Num. 3 (2006) Fiona Walls Discursive practices as cultural cargo2 Charoula Stathopoulou Exploring informal mathematics of craftsmen in the designing tradition of 'xysta' at Pyrgi of Chios9 Kai Horsthemke Ethnomathematics and education: some thoughts15 Erling Torkhildsen Communication: A mathematics teacher's apology20 Donna Kotsopoulos Communication: Researching linguistic discrimination21 Alf Coles Communication: In search of practical wisdom22 Dvora Peretz Teaching for understanding for teaching24 Denise S. Mewborn , Andrew M. Tyminski Lortie's apprenticeship of observation revisited30 John Lannin , Brian Townshend , David Barker The reflective cycle of student error analysis33 Dor Abrahamson , Matthew Berland , Benjamin Shapiro , Joshua Unterman , Uri Wilensky Leveraging epistemological diversity through computer-based argumentation in the domain of probability39