“…Not all hypertext systems have been found to enhance learning, though. Poorly designed systems can either have no effect on learning or lead to disorientation and cognitive overload (Baylor, 2001; Calisir & Gurel, 2003; Dias, Gomes, & Correia, 1999; McDonald & Stevenson, 1996, 1998; Waniek, Brunstein, Naumann, & Krems, 2003; Zhang, Han, Zhu, & Zhu, 2002). These potential problems are partly addressed by providing good navigational aids (Chou, Lin, & Sun, 2000; Dias et al, 1999; Lee, 2002; Lee & Tedder, 2004), although research has also shown individual differences in how users react to variations in site organization.…”