%J International Seminar on Innovation in Mathematics and Mathematics Education %D 2014 %I Departement of Mathematics Education Faculty of Mathematics and Natural Science Yogyakarta State University %T Educational Design Research: Developing Students’ Understanding Of Measurement Units Of Area %A . Susilahudin Putrawangsa1, Monica Wijers2 Agung Lukito3, Siti M A %L UNY24250