Although the literature reports a great diversity of views concerning the processes of conceptual change (Cosgrove, Osborne, & Carr, 1985; Hewson & Hewson, 1992; diSessa & Sherin, 1998), two conceptual change levels are identified: the first level involving the addition of new facts and the generation of new relations between existing concepts, and the second level involving changes to fundamental concepts and conceptual structures (Vosniadou &