“…In a case study of one student, Taber (1995) demonstrated that the student's alternative framework about charges acted as a block to learning about chemical bonding. Some studies suggest that such "blocks" or "obstacles" to learning need to be weakened or even abandoned before a new conception can develop (De Posada, 1997;Hewson & Thorley, 1989), and that such conceptual change requires rational considerations on the part of the learner (Carey, 1999;Strike 1 Different authors have used different labels for such nonscientific ideas, implicating different assumptions about their nature and properties (Smith et al, 1993;Tytler, 1998). Here, we will use the term "misconception" in a general sense, without any particular connotations, and interchangeably with "nonscientific idea," in agreement with several other authors (Nicoll, 2001;Smith et al, 1993;Özmen, 2004).…”