4Moreno, R. , & Mayer, R. E, A Coherence Effect in Multimedia Learning :The Case for Minimizing Irrelevant Sounds in the Design of Multimedia Instructional Messages. Journal of Educational Psychology, 2000,92 ( 1 ) : 112-125.
5Kalyuga, S. , Chandler, P. , &. Sweller, J. "Managing Split- Attention and Redundancy in Multimedia Instruction," Applied Cognitive Psychology, 1999,13,351 - 371.
6Sweller, J. & Chandler, P. "Why Some Material is Difficult to Learn," Cognition and Instruction, 1994, 12(3):185-233.
