On 4 April 2007, The Sydney Morning Herald reported a f inding from research done by the University of New South Wales (UNSW) that our brain can process and retain information better if information is digested in either the verbal or written form, but not both at the same time (Patty, 2007). According to John Sweller, Emeritus Professor from the School of Education in UNSW,

It is effective to speak to a diagram, because it presents information in a different form. But it is not effective to speak the same words that are written, because it is putting too much load on the mind and decreases your ability to understand what is being presented (Patty, 2007).

This finding supports the research by Garber (2001) as well as Felder and Brent (2005). After the Space Shuttle Columbia disaster which killed seven astronauts on 1 February 2003, the Columbia Accident Investigation Board at National Aeronautics and Space Administration (NASA) partially blamed Microsoft PowerPoint, arguing that the NASA engineers who assessed the wing damage had earlier presented their findings in PowerPoint slides that were crammed with too many bullet points (see Figure 1). Not only were the slides confusing, they also failed to highlight the significance of the damage to the NASA management (Thompson, 2003).

As I am fully aware of the pitfalls of cramming too much text into one slide, I have been experimenting with using simple slides which have only a few keywords or diagrams in my teaching. In this article, I would like to share my experience and my students' feedback on using simple slides in my teaching.

Keeping Slides Simple

In preparing the PowerPoint slides for my class, I strive to reduce each slide to its bare essentials. Important facts are always presented and explained using graphical or textual representations as far as possible. For example, I redesigned the slide in Figure 1 to show only the most critical point in Figure 2. Two sample slides from my class, CS2105 "Introduction to Computer Networking", are shown in Figures 3a and 3b.

Stripping each slide down to its simplest form allows students to focus on my explanations. Putting the right information on the slides also helps me communicate the important points across without distracting students with unnecessary words.

Figure 1. A sample slide from the Debris Assessment
Team’s briefing to the Mission Evaluation Board at NASA
[Source: Parker, Chao, Norman & Dunham, (2003)]

Figure 2: A redesign of the slide in Figure 1 with
emphasis on the most critical point

Figure 3a. A PowerPoint slide explaining how Cyclic
Redundancy Code (CRC) is computed

Figure 3b. A PowerPoint slide listing the range of
IP addresses reserved for private networks

Impact of Using Simple Slides on Teaching

Preparing such slides has helped me and my teaching in several ways. Firstly, I now have to think carefully about the main point I want to convey to students when I prepare each slide. This is different from preparing slides that are full of bullet points; I tend to just dump data and text mindlessly into the slides. Secondly, preparing simple slides also makes me think and come up with the best and simplest method to explain a particular concept to students. Finally, simple slides force me to be better prepared for my lectures since there are often no words on the slides to guide me, and thus help me avoid the common 'sin' of reading from the slides.

Student feedback showed that my presentations were great. Students were able to understand many complex concepts I taught in class and some students explicitly credited this to how I used diagrams in my slides. However, there were also students who complained that my slides were 'bad'.

Impact of Using Simple Slides on Learning

Although I used the slides as visual aids in my lectures, students who wanted to use the slides as notes said my slides were not useful for revision and preparing for upcoming lectures. My slides are useless by themselves without explanation. Thus, students often had to refer to my explanation by watching the webcast lectures when they revised and this was a time consuming task.

Since my slides cannot be used for revision, students had to take their own notes. In a short survey on my students taking CS2105 "Introduction to Computer Networks" in Semester 2, Academic Year 2006/2007, 67% of students said they took notes during my lecture. While 64% of students agreed that they can understand the material better when they make their own notes, 60% said they cannot focus on the verbal explanation and take notes simultaneously. Some students said that they felt insecure because they were afraid they might have missed out some important information in their notes.

Summary

The best way to present information is to use simple slides with diagrams without too much text or too many bullet points. Though this practice works best in both business and academic presentations, students who are accustomed to using PowerPoint slides for revision may not find such slides useful. One obvious way to address this is to provide a separate set of revision notes using the 'notes' function in Microsoft PowerPoint. Alternatively, the lecturer could also pause between slides to give students more time to take their own notes during lectures. With a little thought and creativity, lecturers can deliver their presentations effectively using simple slides, help students with revision and avoid 'death by PowerPoint'.

References

Felder, R.M. & Brent, R. (2005). 'Death by PowerPoint'. Chem. Engr. Education, Vol. 39, No. 1, pp. 28-29.

Garber, A.R. (2001). 'Death by PowerPoint'. (Last accessed: 20 August 2007).

Parker, P.; Chao, D.; Norman, I. & Dunham, M. (2003). 'Orbiter Assessment of STS-107 ET Bipod Insulation Ramp Impact', (Last accessed: 20 August 2007).

Patty, A. (2007, April 4 ). 'Research Points the Finger at PowerPoint'. The Sydney Morning Herald (Last accessed: 20 August 2007).

Thompson, C. (2003, December 14). 'PowerPoint Makes You Dumb'. New York Times: The 3rd Annual Year In Ideas Issue(Last accessed: 20 August 2007).