Program 12th eColloq

Monday, October 6th, 2014, 4-6 pm (CET, Stockholm, Berlin Rome)

4:00-4:10 Connect

4:10-4.35 Martijn Wackers (Delft University of Technology / Leiden University, The Netherlands): Towards more evidence-based public speaking advice: the effect of summarizing in an educational presentation on audience information retention (SLIDES)

How can a public speaker make a message memorable? Public speaking textbooks offer an abundance of advice on rhetorical strategies. Tell ‘em what you told ‘em, providing a recapitulation or summary, is frequently mentioned: a corpus research into 40 public speaking textbooks published from 1980 to 2009 shows that more than half of the textbooks authors associate the summary with information retention (Besterveld, 2012). The summary also seems connected to the principle of ‘organisation’ people use to encode and memorise information (Baddeley et al., 2009).

However, public speaking advice on how to use a summary is seldom clear-cut and sometimes contradictory. To obtain more insight into the effect of a summary when used in a specific presentation context, an experiment was carried out at Delft University of Technology. To what extent can a summary enhance audience information retention and appreciation of an educational presentation?

Three versions of a short educational speech were constructed and videotaped: (1) a version without a summary altogether, (2) an ‘indicative’ version with a mere statement of the main points and (3) an ‘informative’ version with a more elaborate, content-focused summary of the speech’s main points. The versions were shown to separate, comparable audiences of students (N = 250). Afterwards, the information retention and audience appreciation of the closing statements were measured with a questionnaire containing open and multiple choice questions. A posttest was carried out three weeks after the original viewing. Results indicate that the audience’s information retention of the summarised main points and the appreciation for the speech wrap-up was higher for the informative version compared to both other versions.


Baddeley, A., M.W. Eysenck & M.E. Anderson (2009). Memory. Hove: Psychology Press.

Besterveld, B. (2012). “Recall too, the memorable words of Neil Armstrong…”. A research into the quantity, content and support of retention advice in English-language public speaking textbooks from 1980 to 2009. Master thesis, Faculty of Humanities, Leiden University.

4:35-4.55 Group Discussion


5.05-5.30 Jos Hornikx (Radboud University Nijmegen, The Netherlands): Are people sensitive to high-quality arguments? The role of distraction (SLIDES)

Evidence in support of claims can be said to be of high(er) quality if it respects norms developed for argumentation schemes. Experimental work has shown that claims supported by high-quality evidence are more persuasive than claims supported by low-quality evidence. However, Hoeken and Hustinx (2007) showed that this effect was only observed in short texts (a claim with evidence), but not in longer texts (where information unrelated to the evidence was added at the end of the text). The current experiment was conducted to examine whether this effect of text length could be explained by distraction (the additional text at the end distracts the reader) or by dilution (the additional text makes the fragment less diagnostic for claim evaluation). Participants (N = 629) read two texts with high/low-quality evidence. The text was presented in three versions: short, long with additional information at the end, or – new in comparison to Hoeken and Hustinx (2007) – long with additional information at the start. The data found support for the distraction explanation: an effect of evidence quality on persuasiveness was observed in the short text, and in the longer text with additional information at the start, but not in the longer text with additional information at the end.

5:30-5.50: Group discussion


To participate as a discussant (n.b. ”listening in” is fine, too), please register now.