Effect of modality and speed control presentation on efficiencymultimedia instruction in second grade students high school

The present study aimed to reduce cognitive load and to increase the efficiency of teaching in a computer-based multimedia learning environment. Educational content were presented in two modality (Narration Vs. on screen text) and Controlling the pace of presenting content provided (learner-paced Vs. system-paced) in a computer-based multimedia environment. The content of present study presented the meaningful frames of lightening formation during steps in form of casual string in the form of an animation on 100 secondary school female students in Tehran. The instrument of collecting the information included retention and transfer tests and testing sheets of cognitive load. This study carried out in pure experimentally ( factorial design). Resultsshowed that the group narration under cognitive load, resulting in higher efficiency than the group had on screen text. The interaction of modality and controlling the pace of presenting training in performance efficiency was also significant. Findings confirmed moderating effect controlling the pace of presenting on modality in a multimedia learning environment. The results are explained by cognitive load theory and cognitive theory of multimedia learning