Date of Award

Summer 2016

Document Type


Degree Name

Doctor of Philosophy (PhD)


STEM Education & Professional Studies

Committee Director

Ginger S. Watson

Committee Member

John W. Baaki

Committee Member

Peter Baker


Online learning and the use of multimedia is a quickly growing element of higher education. This experimental research study examines five common audio and video presentation designs to inform evidence-based practices that can be applied by instructional designers as they develop content for online learners. Specifically, this experiment compares instructor-only, slides-only, dual-windows, video-switching, and superimposed-slides multimedia designs in terms of learning effectiveness, perceived instructor credibility, instructor immediacy, and cognitive load created by each design. This study included a diverse sample of adult learners who were randomly assigned to treatment groups. A total of 171 participants completed the study and responded to the NASA Task Load Index (TLX) used to gauge task and cognitive load, the credibility and immediacy survey, and the 20-item post-test. A series of 5x1 Analyses of Variance and Tukey post-hoc calculations were conducted to test for statistically significant differences between groups. The results suggest that a balance can be established between instructor credibility and immediacy by showing both the instructor and instructional content during online classes. The five multimedia designs can yield similar results in recall and comprehension as long as audio, video, and content quality is a design priority. The results also indicate that the design of instructional methods has a greater impact on learning than the device used to receive that instruction. Media and technology are a means to deliver pedagogy and foster communication; it is up to instructors and designers to use evidence-based best practices such as these to build optimal learning environments and instructional systems.


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