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Predicting user activity to make the web fast presentation


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Arvind Jain and Dominic Hamon

Published in: Technology, News & Politics
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Predicting user activity to make the web fast presentation

  1. 1. Predicting User Activity to Make The Web Fast Velocity Conference 2012 Arvind Jain and Dominic Hamon Google
  2. 2. How fast is the web today?● Chrome ~ 2.3s/5.4s page load time (median/mean)● Google Analytics ~ 2.9s/6.9s page load time (median/mean)● Mobile ~ 4.3s/10.2s page load time (median/mean)
  3. 3. Web page size over time
  4. 4. Making the web fast● Faster browsers● Faster networks● Faster hardware● Faster pagesBut not enough to make the web Instant...
  5. 5. The time between requests● ~ 3 seconds to type a URL● ~ 15 seconds to select a search result● Plenty of idle time● Why not use it?
  6. 6. Predict and Prerender● Predict user navigation or follow advice from page <link rel=prerender>● Fetch all resources for a page● Render to a hidden tab● Swap in when user navigates
  7. 7. Chrome Omnibox Prerendering● Already provide suggestions to the user● Opportunity to learn browsing behaviour● Ability to develop good prediction model● Little contention for resources
  8. 8. Implementation details● Track whether the user takes a suggestion● Map users text input to suggestion and hit/miss counts● Given user input and suggestion, calculate confidence C: ○ C = H / (H + M) where H is the hit count, M is the miss count
  9. 9. Implementation example● User types c● Suggestions are: ○ ○● User types n● Omnibox shows cn● Suggestion is● User selects
  10. 10. Implementation example (cont.)● We store:{ c, { {, 1, 0 }, {, 0, 1 }, }, cn, { {, 1, 0 }, },}
  11. 11. Implementation example (cont.)● Over time, this data structure evolves to something like: View your data at chrome://predictors in Chrome 20
  12. 12. Implementation example (cont..)● User types c● Suggestions are: ○ ○● is selected by default● Confidence is C = 1● Start prerendering
  13. 13. Demo
  14. 14. Key results● Coverage ○ Almost a third of Omnibox navigations are prerendered● Accuracy ○ About 90% of those prerenders are used● Instant ○ Between 15% and 20% of Omnibox navigations are instant (<10 ms)● Median time saved ○ ~1 second (>40%) per Omnibox navigation
  15. 15. Total time saved per day Omnibox: Over 10 years Search: Over 20 years
  16. 16. Why should you care?● Your site will be prerendered at some point by some users● Check your site is compatible● Page Visibility API● Consider <link rel=prerender> for your own site
  17. 17. Thank youArvind Jain and Dominic Hamon Google