The associated blog post is at http://www.lognormal.com/blog/2012/10/03/the-3.5s-dash-for-attention/ When searching for something online, people often open multiple results in browser tabs and switch to the one that loads first. It’s a race for the user’s attention, but usually there’s only one medal. Just as in sport, the web is fiercely competitive and people expect more from it each year. Last year’s winning performance is this year’s new baseline. As a result developers must answer complex questions to stay in the game: How do users perceive the performance of my site? What do they expect and am I meeting their expectations? What new metrics should I be collecting to answer these questions? In this talk, Buddy and Philip will answer most of these questions, and cover some of the insights gained from studying real user performance data over the last few years. We’ll also cover tools that you can use, both free and commercial, to arm you with the information you need to win Gold.

1. Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 1

2. The 3.5s dash for attention and other stuff we
found in RUM
Buddy Brewer, Philip Tellis
Velocity EU 2012 / 2012-10-03
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 2

3. Jean-Antoine Nollet
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 3

4. Mr. Souders
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5. https://github.com/lognormal/boomerang/
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 5

6. Never underestimate the bandwidth of a mail horse
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 6

7. World-wide bandwidth
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8. What do users expect?
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 8

9. Gold or Bronze?
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 9

10. What delighted users a few years ago is now an expected
baseline, the absence of which will frustrate.
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11. Should you delight?
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 11

12. Or frustrate?
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13. Delighting changes the baseline
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14. Delighting changes the baseline
(Frustrating does too, but we don’t want to go there)
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15. So where’s the web today?
Velocity EU 2012 / 2012-10-03 The 3.5s dash for attention and other stuff we found in RUM 14

16. Log-Normal Distribution
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17. Log-Normal Distribution
The logarithm of the x-axis follows a Normal distribution
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18. Log-Normal Distribution
Performance data does not always follow a "pure" Log-Normal
distribution
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19. Look at the entire spread
...
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20. Look at the entire spread
which often approaches an infinite width
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21. • 0.8% of hits are fake/abusive
• 0.2-0.5% of hits are from a stale cache
• 0.1% of hits are absurd
• Timestamps in the future (or past depending on how you
interpret it)
• Bots ignore robots.txt across domains
• "Interesting" caches/copies
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22. Even with beacons, you need to sanitize your input
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23. Once you get past the cruft, you can really measure users
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24. How does performance
impact human behavior?
Wednesday, October 3, 12

25. 8 million pages
1.5 million visits
50 different dimensions
Wednesday, October 3, 12

26. very fast sessions had high bounce rates
70.00%
52.50%
35.00%
17.50%
0%
0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30
Wednesday, October 3, 12

27. bounce rate vs. load time
70.00%
52.50%
35.00%
17.50%
0%
1 3 5 7 9 11 13 15 17 19 21 23 25 27 29
Wednesday, October 3, 12

28. bounce rate vs. DOM interactive
70.00%
52.50%
35.00%
17.50%
0%
1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5
Wednesday, October 3, 12

29. bounce rate vs. front end time
80.00%
60.00%
40.00%
20.00%
0%
0.5 2 3.5 5 6.5 8 9.5 11 12.5 14 15.5 17 18.5 20 21.5 23 24.5 26 27.5 29
Wednesday, October 3, 12

30. is my web site performance toxic to my
users?
http://www.flickr.com/photos/21560098@N06/3796822070
Wednesday, October 3, 12

31. LD50 - when do half the users bounce?
http://www.flickr.com/photos/thecosmopolitan/6117530924
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32. Bounce rate >=50%
Back end time 1.7 sec
DOM Loading 1.8 sec
DOM Interactive 2.75 sec
Front end time 3.5 sec
DOM Complete 4.75 sec
Load event 5.5 sec
Wednesday, October 3, 12

33. Browsers by Load Time
70.00%
52.50%
35.00% LD50
IE: 3.6 sec
17.50%
Firefox: 5.6 sec
Chrome: 6.5 sec
0%
1 1.4 1.8 2.2 2.6 3 3.4 3.8 4.2 4.6 5 5.4 5.8 6.2 6.6 7 7.4 7.8 8.2 8.6 9 9.4 9.8 10.2 10.6 11 11.4 11.8 12.2 12.6 13 13.4 13.8 14.2 14.6 15
IE Chrome Firefox
Wednesday, October 3, 12

34. Browsers by DOM Interactive
90.00%
67.50%
45.00%
LD50
22.50%
IE: 1.8 sec
Firefox: 3.1 sec
Chrome: 4.4 sec
0%
0.5 0.7 0.9 1.1 1.3 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 4.1 4.3 4.5 4.7 4.9 5.1 5.3 5.5 5.7 5.9 6.1 6.3 6.5 6.7 6.9 7.1 7.3 7.5 7.7 7.9 8.1 8.3 8.5 8.7 8.9 9.1 9.3 9.5 9.7 9.9
IE Chrome Firefox
Wednesday, October 3, 12

35. Countries by Load Time
90.00%
67.50%
LD50
DE: ? sec
45.00% US: 5.0 sec
GB: 11.5 sec
CA: 13.5 sec
AU: ? sec
22.50%
0%
1 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7 7.5 8 8.5 9 9.5 10 10.5 11 11.5 12 12.5 13 13.5 14 14.5 15
US CA DE AU GB
Wednesday, October 3, 12

36. Available Bandwidth
GB AU World
Wednesday, October 3, 12

37. Future directions
What is the LD50 for your site?
Other bounce rates? 40%? 30%?
Other variables? (critical content
visible, etc)
Other behaviors? Conversions,
revenue, pages per session, actions,
when do people make tea?
Wednesday, October 3, 12

38. Questions?
Buddy Brewer @bbrewer
Philip Tellis @bluesmoon
Wednesday, October 3, 12

39. Credits
• Usain Bolt – Sum_of_Mark on flickr
• Douglas Mail Carrier – Svadilfari on flickr
• Angel Delight – Auntie P on flickr
• Frustrated – Kevin Lawver on flickr
• Jean-Antoine Nollet – (Public Domain) Wikipedia
• 100 metre dash – on NY Times
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