Sunday 28 February 2010

4: Tufte on PowerPoint


Edward R. Tufte, The Cognitive Style of PowerPoint: Pitching Out Corrupts Within, (2nd Edition 2006)

I am currently developing project on the National Police DNA Database (NDNAD) and have been thinking about the use of racialised data in politics and policy-making for some time. Recent contact with media studies has been helpful - opening up new questions about the ways in which software facilitates and shapes the day to day workings of systems of data gathering and use. I have come to realise also the importance of how data is represented via tables, charts, and presentations - thinking about, for example, the format of reports on the governance of the NDNAD.

During a great visiting lecture by Sean Cubbit (which can be seen here and slides here), he mentioned Edward Tufte's wonderful little book(let?) about PowerPoint. Tufte's argument, based on long experience as an expert on 'analytical design', examination of case studies, and comparison with other presentation techniques, is that PowerPoint, particularly its ready-made templates "reduce the analytical quality of serious presentations of evidence." PowerPoint encourages the simplification of evidence and breaks up analytical narratives into disjointed points that are often inappropriately organised and ranked to fit into the slide structure. For example, statistical evidence is often unhelpfully over-summarised and, in some cases, turned into nonsense using PowerPoint's graphical software. Bullet point lists tell us little about connections and causal relationships. Moreover, the ritual of the PowerPoint presentation - the reading out of low-content slides in semi darkness to a passive audience limits thought and learning.

" ... formats, sequencing, and cognitive approach should be decided by the character of the content and what is to be explained, not by the limitations of the presentation technology." (p6)
Tufte argues that PowerPoint bears the imprint of its origins - it belongs to top-down corporate bureaucracies and to marketing. These run counter to good teaching, open debate and a respect for evidence. Often a more appropriate form of presentation is using handouts written in linked sentences and paragraphs. Contrary to the assumption of PowerPoint, people can and should be shown large quantities of statistical data e.g. detailed tables which they can then digest and interpret for themselves (Tufte illustrates this brilliantly by including a fascinating cause of death table with nearly 2000 separate entries!)

Tufte shows how the reliance on PowerPoint presentations in NASA was a key reason why scientists failed to prevent the 2003 space shuttle disaster. Rather than producing written technical reports on the risks with detailed discussion of evidence, scientists presented to decision-makers who were left to judge the significance of possible risks listed as short bullet points in the 'anti-narrative' of a PowerPoint slideshow. Technical discussion in NASA took place by PowerPoint pitch rather than written reports despite the inability of the software even to handle basic engineering notation!

Tufte argues that PowerPoint's popularity rests on a dangerous myth that people suffer from information overload and benefit from low-content and a summary of few hundred words. But in many situations, detailed information is essential and in any case often people better understand if allowed to explore actively the detail of an issue using a variety of media rather than merely hearing a headline summary.

"Rather than providing information, PowerPoint allows speakers to pretend that they are giving a proper talk, and audiences to pretend that they are
listening. This prankish conspiracy against evidence and thought that should provoke the question. Why are we having this meeting?"
(p31)
Implicit in Tufte's analysis is another question: how and why did PowerPoint become so ubiquitious and how has it in the process altered education and corporate life. Food for thought for me both as a teacher and as a researcher.

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