A popular view of online communities is that they transcend time and place. As threads and comments are posted, however, the ensuing online-discussions unfold over time. Not only does timing determine which threads participants will see first when they arrive, but also which comments have not already been extensively replied to.
By affecting who interacts with whom during the circadian cycle, time-pressure at the level of threads could in turn shape the social ties that form. Coupled with time-zone differences, this would make online communities a lot less global than generally believed.
A case-study of the Hacker News community was conducted to measure time-effects. Hacker News caters to people interested in web-startups. It has approximately 100,000 unique daily visitors from all over the world, and receives about 2,500 posts per day. Fourty days of data was collected, and geo-locations were acquired for three thousand users.
In a preliminary analysis, strong time-pressure effects were found at the thread-level. For social ties between users, moderate, but statistically significant effects were found as well; especially for users at the edge of the network. Even the two-week gap between the introduction of daylight savings time in the US and UK, was found to have an impact on peoples network distance during that time.
These findings might limit the validity of purely social interpretations of on-line reply structures, as well as the extent to which (large) on-line communities can be considered real communities, rather than imagined communities that are primarily shaped by the flow of conversation.
Fostering Friendships - Enhancing Social Bonds in the Classroom
The Invisible Hands of Time: How Timezones Shape Online Communities
1. The Invisible
Hands of Time:
How Timezones Shape
On-line Communities
Wybo Wiersma
Oxford Internet Institute
mail@wybowiersma.net
23 May 2013
2. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Introduction
In this talk I:
• Will catch time red-handed
• At impacting the structure an on-line community
namely; Hacker News
• Time sets the stage for interaction
Your speaker:
• 1st year DPhil student
at the Oxford Internet Institute
• Sr. Software engineer in Sillicon Valley last year
3. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Hypotheses
4. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Hypotheses: Why care
Social interpretations of reply-structures
• Are common in SNA
reciprocity, bonding, friendship
Underlying assumptions:
• On-line communities
work similarly to off-line ones
• On-line Global Village
is actually global
Yet if time foremostly determines replies
• Social explanations might be spurious
5. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Hypotheses: Previous work
Papers on reply-structures
• None circadian, none on 24-hour scale
More remotely relevant
• How threads unfold on Slashdot (Kaltenbrunner)
• Usenet discussions unfold over multiple days
• Cycles in MUDs/Internet/mobile traffic
6. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Hypotheses: Theory
Social mechanisms (Elster, Hedstrom)
• Look at individual interactions
micro to macro emergence
Structuration theory (Giddens)
• Environment affords/shapes choices
besides, and through agency
Imagined communities (Anderson)
• On-line communities like nation states
not based on personal social ties
7. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Hypotheses: Why care
Hypothesis 1)
• There is a time-pressure effect at level of threads
users mainly reply to new threads/posts
threads are mostly saturated within a few hours
Hypothesis 2)
• What appears social in reply-structures
is dictated by the thread time-pressure effect
and peoples different circadian rythms
8. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads
9. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: Hacker News
Hacker News is like Slashdot
• Can comment on stories
but posted by members
• Rating / time determines ranking
(r − 1)/(t + 2)1.8
separates time effects from ordering
• 100k daily visitors (large)
• Ran by Paul Graham (Y-combinator incubator)
for startup community
very international
10. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: A specimen
11. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: User locations
12. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: Data
Data collected
• Over 40 days (in 2011)
3.5k threads
100k posts
by 13.3k users
So 90 threads, 2.5k posts per day
13. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: Created per hour
14. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: Time pressure effects
Time pressure effect
• Threads created in time
discussions unfold over time
• People arrive at different times
new threads seen first
duplicate replies not appreciated
early replies read more
• Thus new threads (most productively) replied to
Time determines which threads people reply to
• Thus whose posts they interact with
15. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: Posts hours after prompt created
16. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: Replies clock
17. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Networks
18. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Networks: The social fabric
Time-pressure effects
• Confirmed at thread level
most replies are to new threads
Social interpretation of reply-networks
• Largely spurious if time determines
who people maintain ties with
On-line communities
• Would be largely imagined communities
19. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Networks: Types
Reply-networks
• Whole
unidirectional replies sufficient
• Core
reciprocated replies (cutoff > 3)
Colouring
• 3-hour sliding windows
in which user posts most
• 8:00 - 11:00,
9:00 - 12:00, etc
• Same colouring as replies clock
20. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Networks: Whole
21. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Networks: Core (both > 3)
22. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Networks: Core directed (any > 6)
23. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Networks: Clocks core (> 5) vs periphery (< 6)
24. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Threads: Prolific users aligned by timezone
25. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Statistics: Numbers don’t lie
26. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Statistics: Permutation test
Tested fraction of ties that showed:
• Reciprocity
• Transitivity (triadic closure)
24 one-hour windows over 40 days:
• Base-case
networks for same window every day
• 10k permutations
different random window every day
27. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Statistics: Permutation test
Reciprocity in 24 same 0.113 - 0.148
• For random windows
average 0.087 (never larger, p 0.000)
Transitivity in 24 same 0.016 - 0.025
• For random windows
average 0.014 (41/10k larger, p 0.004)
Very significant time-effects
28. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Statistics: Least squares distance
Median circadian time-difference
• Between posts
per network-distance
10 minutes per hop (1 to 4 hops)
• in core (> 3 reciprocated)
30 minutes per hop (4 hops)
• in periphery (< 6 posts)
29. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Statistics: Daylight savings time
Daylight savings time is introduced
• In a phased manner between the UK and US
• US (13th of March) two weeks earlier than UK (27th)
US West Coast and UK users compared
• Distance smaller after US DST introduced
and larger again after UK DST
• 8 Hour-difference reduced to 7 for two weeks
3.65 to 3.53 (0.12 hop distance)
Small, but highly significant difference
30. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Conclusion: Time’s up
31. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Conclusion
Time-pressure effects
• Confirmed at thread level
most replies are to new threads
Time effects on network
• Very significant (but small) effects
• Stronger at periphery than at core
core users on-line 20/7, bridge
Hands of time set the stage
Limits:
• Measures/statistics
• Different for different communities
32. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
Questions
Any questions ?
33. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
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Wybo Wiersma
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Wybo Wiersma
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49. The Invisible
Hands of Time:
How Timezones
Shape On-line
Communities
Wybo Wiersma
Introduction
Hypotheses
Threads
Networks
Statistics
Conclusion
Questions
References
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