Effects of Redundancy and Paraphrasing in University Lessons: Multitasking and Cognitive Load in Written-Spoken PowerPoint Presentation

This paper is about the use of a widespread teaching tool: the slide presentation used in face-to-face, system-paced university lessons. It is produced by lecturers to support students’ comprehension during listening; nevertheless it poses elaboration requests to the audience which should be taken into consideration at the planning stage and in formulating its verbal content. The paper reports the results of a survey conducted with 163 University students who were asked to listen to a lecture accompanied by a PowerPoint presentation, prepared according to the most frequent formats. The written presentation had 3 degrees of concision/redundancy: it had a fully redundant with the oral message, partially redundant (main points in key words), or had a different linguistic form (paraphrase of the message). Furthermore, information in written text and spoken message could have had the same order or they could be scrambled. The results showed that, subjectively, students judged comprehensible every kind of presentation. However, learning tests demonstrated that paraphrasing negatively affected learning, while changes in the order of presentation did not, at least in the synthetic main point – key word presentations. The study suggested that the concise, only partially redundant, presentation is the one which leads to better results, both in the ordered and in the scrambled version.