Podcasting by synchronising PowerPoint and voice: What are the pedagogical benefits?

The purpose of this study was to investigate the efficacy of audio-visual synchrony in podcasting and its possible pedagogical benefits. `Synchrony' in this study refers to the simultaneous playback of audio and video data streams, so that the transitions between presentation slides occur at ''lecturer chosen'' points in the audio commentary. Manufacturers of lecture recording software (e.g. ProfCast) would have us believe that the synchrony of image and audio should improve the learning experience. We have yet to see in the literature any empirical evidence to support this hypothesis. In our study, 90 participants in two groups undertook two electronic lectures (e-lectures) on two separate topics, the subject matter of neither was familiar to them beforehand. Each group experienced one ''synchronous'' presentation (e-lecture) of one of the topics, and one ''separate'' presentation (i.e. PowerPoint and audio files separately presented) of the other topic. Each group therefore experienced both ''synchronous'' and ''separate'' delivery and they were then given an MCQ test that assessed five levels of Bloom's taxonomy. Results show no differences in innate ability between the two groups but the evidence supported our primary hypothesis in that statistically significantly higher test scores were seen when participants viewed a synchronous e-lecture; these scores were accounted for by subjects' performance at three of the five levels of Bloom's taxonomy. Qualitative `attitude' survey results also displayed participant preference towards the synchronous over the asynchronous mode of delivery, and in spite of general acceptance of the proposed benefits of electronic proceedings, a majority preference towards traditional rather than electronic lectures. Despite this conservatism, this paper explores in more detail the potential benefits of podcasting via synchronous PowerPoint and voice.