Psychology of
performance




Stoyan Stefanov, @stoyanstefanov
June 23, 2010
Velocity
Perception
Perception
Perception
Perception
Durations
               actual
            expected
            perceived
                rem’d

                 time
Time perception
•  UCLA – 53s -> 67s -> 91s
     (dopamine)
•    Age
•    Geography - NY vs. LA
•    Culture, climate
•   ...
Time perception
•  Clock is usually faster
•  Long durations are harder
   to judge
When the time stops
•  Athletes
•  Martial arts
Remembered time
•  Emotional state
•  Pleasant vs. painful
   memories
•  “hit vs. smash” speed –
   34/40.5 mph
Unpleasant memories
•  34sec fake assault on
    campus
    -> 81 sec (~250% off)
•  30 sec bank robbery video
   -> 2 day...
Temporal illusions
•  Kappa effect
     time 1 =        time 2



Longer part of a journey feels
  slower
It feels slower when…
•    Unpleasant
•    Unknown
•    Boring
•    Too much to keep track

•    Never ever put too many
•...
Study of frustrations
•  University of Maryland
•  Slow worse than pop ups
•  1/3 to ½ the time lost in
   frustrations
• ...
Effect of waiting
•  Irritation
•  Stress
•  High cholesterol


•    ☠
Feels faster when…
•  Task is successful
•  Responsive system
•  Progress
•  Informed
Expectations
Maister’s first law of service:

Service =
   Perception - Expectation
Expectations
•  Brand name
•  Pre-existing bias
Managing expectations
•  Provide feedback
•  Wait with a warning is
  shorter
Flow
Mihaly Csikszentmihalyi:
“Positive state of
   consciousness…
We lose sense of
self and time
distorts”
Flow
•  Learning through failure
•  Doing is the reward
Some numbers
PARC research
•  0.1s – instantaneous
•  1s – flow
•  10s – attention
A framework
•  0.1 - 0.2s – instantaneous
•  0.5 - 1s – immediate
•  2 - 5s – flow
•  7 - 10s – captivity


- conversation
RTT – response time test
•  190ms college students
•  Slower when go/no-go
•  Correlation to IQ
Blink of an eye
•  0.3 - 0.4s
Turning a page
Two attempts 1 minute each:
•  Kid A – 31, 27
•  Kid B – 39, 38
•  Dad – 44, 43


1.3 – 2.2 seconds a page
Tips?
Progressive rendering
                        Chunk
                        #1




                        Chunk
         ...
Worst enemy?



        CSS
CSS
CSS
Progress indication
•  We learn the hints
•  Status bar, page title
•  What we hate to see:
Too many indicators
Progress indication
•  Progress is good, not ugly
•  Flicker-free rendering?
Progress indication
•  Immediate responses
   don’t require indicator
•  Lazy drop-downs?
•  TMI: 4-5 words a second
•  Wo...
Prefetch
•  Components
•  DNS
•  favicon
Keep the flow
•  “Idiot” box
•  Back, undo
•  No uncertainty
•  Responsive to commands
Intuitions lie
•  Are you a user?
•  Surprising expectations
•  “Where’s the rest”
•  Paging
Colors and time
•  White feels faster
•  But higher expectations
Help remembered durations
•  Negate effects of waits
•  Show benefits
•  WIIFM
Help remembered durations
•  Reporting time?
Long-running tasks
•  WebWorkers, setTimeout
•  After 10s let people stop or
   leave and come back
•  Don’t report elapse...
First time experience
•  Unfamiliar = slow
•  Optimize empty cache or
   there will be no full cache
Too fast
•  Edit-in-place
•  Yellow fades
Distractimations
Good/bad animations
•  Short and sweet
•  Transitions – nothing pops
   in life
•  Easing animations
Thank you!


Stoyan Stefanov
@stoyanstefanov
http://www.phpied.com
Psychology of performance
Psychology of performance
Psychology of performance
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Psychology of performance

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"Psychology of performance" slides from Velocity 2010.

http://en.oreilly.com/velocity2010/public/schedule/detail/13019

Running PageSpeed - all checks. YSlow - A. So what's next to do? Well, you can cheat! You know that time is relative - one hour with your mother-in-law feels much longer than one hour on the beach. The same way you can bend the perception of the page loading time and make the page feel faster, even though the RTT is the same.

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  • Loved your talk at Velocity. This is a hugely interesting topic, and touches on some things that we've been working on. We actually did a webinar a couple weeks ago that went into how you can use analytics to measure user drop-off based on slow performing pages that break user flow (http://bit.ly/bImeUV). Would love to get your thoughts on that and whether you've actually seen the flow-killing behavior. We'd love to do more research on this if you are interested.

    If you're interested in the slides from the talk, you can find them here: http://drop.io/analyticsflow. Note that the overall topic of the talk is combining analytics with external performance monitoring, and is focused on our product, but I think the overriding story is similar.
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  • And about this book Speed Matters? Publisher: New Riders Press; 1 edition (November 22, 2010)
    November yet?
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  • The video recording of this presentation can also be found online: http://blip.tv/file/3798395.
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Psychology of performance

  1. 1. Psychology of performance Stoyan Stefanov, @stoyanstefanov June 23, 2010 Velocity
  2. 2. Perception
  3. 3. Perception
  4. 4. Perception
  5. 5. Perception
  6. 6. Durations actual expected perceived rem’d time
  7. 7. Time perception •  UCLA – 53s -> 67s -> 91s (dopamine) •  Age •  Geography - NY vs. LA •  Culture, climate •  Time of day, day the week •  Body temperature
  8. 8. Time perception •  Clock is usually faster •  Long durations are harder to judge
  9. 9. When the time stops •  Athletes •  Martial arts
  10. 10. Remembered time •  Emotional state •  Pleasant vs. painful memories •  “hit vs. smash” speed – 34/40.5 mph
  11. 11. Unpleasant memories •  34sec fake assault on campus -> 81 sec (~250% off) •  30 sec bank robbery video -> 2 day later.. -> 150 sec (500% off) -> - 50% diff
  12. 12. Temporal illusions •  Kappa effect time 1 = time 2 Longer part of a journey feels slower
  13. 13. It feels slower when… •  Unpleasant •  Unknown •  Boring •  Too much to keep track •  Never ever put too many •  Bullets points •  On a slide •  Never •  Harder to parse
  14. 14. Study of frustrations •  University of Maryland •  Slow worse than pop ups •  1/3 to ½ the time lost in frustrations •  Frustrations affect all else
  15. 15. Effect of waiting •  Irritation •  Stress •  High cholesterol •  ☠
  16. 16. Feels faster when… •  Task is successful •  Responsive system •  Progress •  Informed
  17. 17. Expectations Maister’s first law of service: Service = Perception - Expectation
  18. 18. Expectations •  Brand name •  Pre-existing bias
  19. 19. Managing expectations •  Provide feedback •  Wait with a warning is shorter
  20. 20. Flow Mihaly Csikszentmihalyi: “Positive state of consciousness… We lose sense of self and time distorts”
  21. 21. Flow •  Learning through failure •  Doing is the reward
  22. 22. Some numbers
  23. 23. PARC research •  0.1s – instantaneous •  1s – flow •  10s – attention
  24. 24. A framework •  0.1 - 0.2s – instantaneous •  0.5 - 1s – immediate •  2 - 5s – flow •  7 - 10s – captivity - conversation
  25. 25. RTT – response time test •  190ms college students •  Slower when go/no-go •  Correlation to IQ
  26. 26. Blink of an eye •  0.3 - 0.4s
  27. 27. Turning a page Two attempts 1 minute each: •  Kid A – 31, 27 •  Kid B – 39, 38 •  Dad – 44, 43 1.3 – 2.2 seconds a page
  28. 28. Tips?
  29. 29. Progressive rendering Chunk #1 Chunk #2 Chunk #3
  30. 30. Worst enemy? CSS
  31. 31. CSS
  32. 32. CSS
  33. 33. Progress indication •  We learn the hints •  Status bar, page title •  What we hate to see:
  34. 34. Too many indicators
  35. 35. Progress indication •  Progress is good, not ugly •  Flicker-free rendering?
  36. 36. Progress indication •  Immediate responses don’t require indicator •  Lazy drop-downs? •  TMI: 4-5 words a second •  Wording: “Please wait”, “Stand by” vs. “Saving…”
  37. 37. Prefetch •  Components •  DNS •  favicon
  38. 38. Keep the flow •  “Idiot” box •  Back, undo •  No uncertainty •  Responsive to commands
  39. 39. Intuitions lie •  Are you a user? •  Surprising expectations •  “Where’s the rest” •  Paging
  40. 40. Colors and time •  White feels faster •  But higher expectations
  41. 41. Help remembered durations •  Negate effects of waits •  Show benefits •  WIIFM
  42. 42. Help remembered durations •  Reporting time?
  43. 43. Long-running tasks •  WebWorkers, setTimeout •  After 10s let people stop or leave and come back •  Don’t report elapsed time
  44. 44. First time experience •  Unfamiliar = slow •  Optimize empty cache or there will be no full cache
  45. 45. Too fast •  Edit-in-place •  Yellow fades
  46. 46. Distractimations
  47. 47. Good/bad animations •  Short and sweet •  Transitions – nothing pops in life •  Easing animations
  48. 48. Thank you! Stoyan Stefanov @stoyanstefanov http://www.phpied.com
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