How can we best use PowerPoint? Three streams of research provide answers: (1) surveys provide student and faculty perceptions, (2) expert presenters give their opinion, and (3) cognitive scientists conduct focused perceptual experiments. I expand on this research by testing existing research findings against actual conference presentations. My C# software automatically analyzes 166 slide presentations to generate numeric slide characteristics. A regression analysis then correlates these characteristics with audience ratings and social media impact. The results generally support existing research, but have two surprising outcomes: (1) only certain types of images generate positive session ratings, (2) high words counts lead to improved social media impact.

1. PowerPoint’s Impact on Conference
Ratings and Social Media Likes
eLearn 2012, Montreal CA
Nathan Garrett, PhD
http://profgarrett.com

2. Slide from Presentation Zen Sample Deck

3. Slide from Presentation Zen Sample Deck

4. Slide from Presentation Zen Sample Deck

5. Slide from Presentation Zen Sample Deck

6. Slide from Presentation Zen Sample Deck

7. Slide from Presentation Zen Sample Deck

8. What does the research
has to say about this?
Can we move beyond opinions?

9. How much better are slides than
transparencies or the blackboard?
Powerpoint improves but not
• Instructor likability • Learning Outcomes
• Organization
• Novelty

10. Cognitive Research
Distractions are bad…
• Animations
• Sounds
• Clip-art / pointless images

11. Why don’t images always help?

12. Testable Ideas
• Reduce unneeded/distracting elements
• Use lots of high-quality pictures
• Use short key phrases, and not full sentences

13. Find some data!
http://www.flickr.com/photos/pinarozger/sets/72157621652734691/

14. Data Source
Conference Presentations Usable Files % Usable
MIX 11 124 87 70%
Oscon 09 144 11 8%
Oscon 10 292 27 9%
Oscon 11 322 41 13%
Overall 882 166 19%

15. Get text attributes for each slide
Standard Dev.
Standard Dev.
Standard Dev.
Paragraphs
Paragraphs
Average
Average
Average
Words
Words
Slides
MIX 11
Slides
33 22 2027 1951 270 211
Oscon 09 46 27 2817 2157 446 342
Oscon 10 26 17 1466 1157 245 209
Oscon 11 32 15 1268 1056 231 188
Overall 33 21 1801 1712 268 220

16. Get image attributes for each slide
Image Count Image Pixels Image Bytes Slide as Jpg
Bytes
Avg Sd Avg Sd Avg Sd Avg Sd
MIX 11
119 95 32.83 33.40 8.53 9.70 2.24 1.65
Oscon 09
59 63 12.98 15.39 5.98 7.89 2.93 1.62
Oscon 10
71 64 11.59 11.58 4.00 3.69 2.13 1.61
Oscon 11
80 53 24.98 27.76 6.50 6.71 2.99 2.63
Overall
95 82 25.51 29.19 7.07 8.27 2.48 1.93

17. Get output attributes for each deck
Star Ratings Star Counts Social Media
Avg Sd Avg Sd Avg Sd
MIX 11
4.6 0.7 3.7 5.6 32.3 34.9
Oscon 09
3.2 1.0 6.2 8.0 - -
Oscon 01
3.4 0.8 9.3 10.5 - -
Oscon 11
3.2 1.0 4.1 3.6 7.6 9.8
Overall
3.9 1.1 5.0 6.8 24.4 31.4

18. Regression shows that images
predict a presentation’s star ratings
Model: Star Ratings R2 = 0.141
Variable Coefficient Significance
(Constant) 4.209 0.000
Slides Size as Jpg -0.578 β 0.000
Slide Count 0.218 β 0.091
Image Count 0.514 β 0.002
Images Per Slide -0.309 β 0.031

19. Regression also lets us see that word
count and image size predicts social
media impact
2
Model: Social Media Impact R = 0.385
Variable Coefficient Significance
(Constant) -33.699 0.002
Star Count 0.463 β 0.000
Star Ratings 0.234 β 0.003
Words Per Slide 0.241 β 0.002
Image Bytes 0.168 β 0.028

20. So…
• PowerPoint has a significant impact on audience
satisfaction
• Complex slides and large number of images
(provided they’re not all on one slide) hurt
session ratings
• High image quality and longer sentences increase
social media shares