Perhaps rephrasing to “wordy PowerPoint Presentations and their effect on learning”
From The Association for Psychological Science
More Talk, Less Chalk: Lexically Sparse Slides Improve Recall of Taught Material
Classroom use of presentation software, whereby information is simultaneously delivered verbally and visually, risks overloading students’ working memory and impairing learning. We compared traditional and lexically-sparse slide presentations, using multiple-choice and short essay answers to assess learning; participants exposed to traditional slides performed significantly worse on their essay answers.
AIMS: To investigate whether sparser visual aids improve recall for audiovisually-presented material, and address the implications of this for best teaching practice.
BACKGROUND: While the value of diagrammatic visual aids in teaching is almost beyond dispute, the use of lexical visual aids has received relatively little scrutiny. Auditory and visual information is initially processed by separate systems, each with its own working memory capacity (Paivio, 1986); cross-modal information delivery thus permits greater efficiency of information processing than unimodal (Chandler & Sweller, 1992). Diagrams accompanied by verbal explanation have indeed been shown to improve understanding and retention of material, relative to all-visual presentation (Mayer & Moreno, 1998). However, lectures accompanied by written slides require students to integrate verbal and visual streams of lexical information, despite evidence that this leads to poorer remembering than when the visual stream is non-lexical (e.g., Allport, Antonis & Reynolds, 1972). We therefore investigated whether using lexically dense visual aids might compromise students’ ability to learn.
METHOD: Three slide presentations were created, each with different lexical content: one used traditional, condensed paragraph-style bullet points; the other two used sparsely-worded text, and in one of these, text was replaced by pictures or diagrams wherever possible. An explanatory verbal narrative was recorded and dubbed onto all three presentations. Departmental ethical approval was obtained prior to data collection. Forty-eight adult native English speakers were each randomly assigned to view one presentation. Learning was tested using 21 multiple-choice questions (MCQs) and three short essay answers.
RESULTS: Prior to data analysis, seven key narrative themes of the presentation were identified by consensus among four independent parties. Blind to participant group, we assessed the number of themes present in each participant’s essay responses, and log-transformed the count data to near-normality. One-way ANOVA identified no significant effect of presentation group on MCQ performance accuracy [F(2,45) = .69, p = .51]. However, a second one-way ANOVA revealed a significant main effect of presentation group [F(2,44) = 3.95, p = .02] on the number of themes recalled in participants’ essay answers. Post-hoc analysis corrected for multiple comparisons revealed significantly worse recall scores for participants exposed to the traditional presentation, compared to those exposed to sparse text only (MD = 1.54, p = .04) and sparse text with pictures (MD = 1.65, p = .02) groups.
DISCUSSION: Slides with dense lexical content did not impede MCQ performance, which relies at least partly on recognising correct answers among distractors. However, results indicate that participants exposed to lexically sparse slides had better recall of thematic content, suggesting that deeper encoding occurs when working memory demands are reduced, and that this may be achieved simply by minimising the number of words on the slide. In presenting competing visual and verbal lexical narratives, instructors may be inadvertently increasing the extrinsic cognitive load (Leahy, Chandler & Sweller, 2003) of taught material, thus making it harder for students to encode lecture content. Smart teaching should attempt to minimise such unnecessary demands on working memory in order to improve students’ recall of material.
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