This document summarizes research on identifying social practices using call detail records from British telephone networks. The researchers analyzed call records linked to survey data from 999 households to study patterns of social contact. They identified different types of calling practices like grapevine calls (where one incoming call prompts multiple outgoing calls to spread news) and batch calls (making multiple outgoing calls in one sitting). Analyzing the timing and direction of calls in sequences allowed the researchers to algorithmically identify calling groups and quantify these practices. The study aimed to develop methods for detecting and analyzing how social practices emerge, persist, and change over time using trace data from communications networks.
Practice hunting with British telephone call records
1. Practice hunting with British
telephone call records
Ben Anderson, Department of Sociology
Dr Alexei Vernitski, Department of Mathematical
Sciences
Dr David Hunter, School of Computer Science and
Electronic Engineering
With data & funding support from BT plc
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2. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
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3. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
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4. So, what are practices?
Entities
a temporally unfolding and
spatially
dispersed nexus of doings and
sayings
Schatzki, 1996
‘habits’, ‘bodily and mental routines’
Why people don’t do
‘permanent dispositions’
what they ‘should’ - Jim Skea, 2011
Reckwitz, 2002;
habituation, routine, practical
consciousness,
tacit knowledge, tradition
Performance Performance often neither fully conscious
nor reflective
Warde, 2005
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5. Three questions that arise...
• If practices are distributed across space and time, how are they to be
defined and recognised?
• How do they develop, expand or retract in spatial and temporal scale?
• If practices emerge, persist and are reproduced and transformed over time
• How can such processes be detected and revealed, and at what scales?
• As present practices are shaped by practices and systems of practice from
the past
• How does this shaping work?
• How do present practices constitute institutions and infrastructures of
the future?
With apologies to: Researching Social Practice and Sustainability: puzzles and
challenges, SPRG Discussion Paper, 2011
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6. Can we observe them?
Image: Anthony B. Wooldridge,
1986
“The recurrent enactment of specific
practices leaves all sorts of “marks” –
diet shows up in statistics on obesity;
heating and cooling practices have effect
on energy demand, and habits of laundry
matter for water consumption.
Identifying relevant “proxies” represents
one way to go.”
SPRG Discussion Paper
Image: Eric Shipton, 1951
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7. 'Marks' and 'proxies'...
• Tried:
• Shadowing/tracking/observation
– Small n, can ask why, investigator effects (?)
– Historical?
• Time use surveys (diaries, e.g. UK ONS 2000, MTUS)
– Big n, non response issues, can’t ask why, complex
data
– Rarely longitudinal, sometimes historical (MTUS)
• Relatively Untried:
• Expenditure Surveys
–
E-Living Time Use Diary 2001 n, proxies for % personscan’t ask why, complex
Big (weekdays), practices, reporting
data
• TechnoTraces
–
Transactions/meters/bills, proxies for practices,
complex data, difficult to access
ONS 2005 Time Use Survey Data (UK, weekdays) % of persons reporting
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8. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
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9. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
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10. Meet the data I
Wave 1 - 1998 Wave 2 - 2000 Wave 3 - 2001
Undefined 6 10
Survey plus diary 1093 649 723
Survey only 668 918 840
16+ survey total 1761 1567 1563
Non-response 273 391 321
Children’s diary 163 82 73
No children’s diary 125 220 208
Child under 9 286 289 231
Total sample size 2608 2555 2406
Number of households 999
Home Online Household Panel 1998-2001 (survey + time use diary)
GB representative sample
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11. Are those who said yes to linkage strange?
• Of the 999, c 60% said yes to call record linkage
• → (self) selection bias?
partner+kid>15
partner+kid>11
partner+kid<12
part,nokid,>55
part,nokid,<56
part,nokid,<36 Yes at wave 2
Yes at wave 1
lonepar,kid>15
No
lonepar,kid<16
un-other rel
alone over 55
alone under 56
0 20 40 60 80 100 120 140 160
N
Home Online Household Panel 1998-2001 (survey + time use diary)
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12. Are those who said yes to linkage strange?
• → (self) selection bias?
Don't know (25% said yes)
Any other company (76% said yes)
Cable TV company (55% said yes)
Mercury/Cable & Wireless (69% said yes)
BT (74% said yes)
0 100 200 300 400 500 600 700 800 900
Number of households
No Yes but calls not logged Yes and calls logged
Home Online Household Panel 1998-2001 (survey + time use diary)
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13. Are those who said yes to linkage strange?
• Logisitic (selection) regression
Said 'yes' to linkage Said 'yes' to linkage and call
records collected
Less likely to be: Less likely to be:
Lone parents (x3) Non-BT (!)
Young couples (x0.2)
More likely to be: More likely to be:
Better off
Home owners (x0.6)
• → no effects for (lots) of other variables including social network responses
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14. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
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15. Ego network sizes
• Biological networks:
• Many nodes with few connections & few
nodes with many connections: y = a/x or y
= a/x2 (log-linear or ‘scale-free’)
• Human calling networks:
• Same principle
• C = number of contacts
• Do we find the same thing?
McCarty et al (2001) Comparing two methods for estimating network
size, Human Organization; Spring 2001; 60, 1; pg. 28
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16. Contact groups (ego networks)
• Survey item:
• N local friends
• N non-local friends
• N local relatives
• N non-local
relatives
Summed for those contacted
at least once a year
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17. Contact groups (ego networks)
• Survey item:
• N local friends
• N non-local friends
• N local relatives
• N non-local
relatives
Summed for those contacted
at least once a year
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18. Contact groups (ego networks)
• But
• Correlation = 0.299 (***) and 0.297 (***)
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19. Contact groups (ego networks)
• So...
– The distributions appear to match reasonably well (but see K-S test)
– But the individual responses do not
Kolmogorov-Smirnov test = -5.528 (***) Correlation = 0.297 (***)
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20. Contact groups (ego networks)
• But...McCarty et al (2001) Comparing two methods for estimating
network size, Human Organization; Spring 2001; 60, 1; pg. 28
Kolmogorov-Smirnov test = sig. Correlation = 0.55 (***)
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21. Contact groups (ego networks)
• Does household type tell us
anything?
• For some, call-records
derived contact numbers
predict survey responses
Couple, children aged > 16
Couple, children aged 11-15
Couple, children aged < 12
Couple aged > 56, no children
Couple aged 36-55, no children
Couple aged < 36, no children
Lone parent, children > 15
Lone parent, children aged < 16
Unrelated persons
Alone, aged > 55
Alone, aged < 56
-1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5
Regression coefficient
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22. Contacting your contacts
• A few people in your
network get a lot of
calls
• Most people get few
calls
• No evidence of
clumping (Dunbar)
This is a familiar curve - Pareto (scale free)
If C = total number of contacts, and f(n) = number of
contacts called n times
Then f(n) = C/(n*(n+1)) if n > 0
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23. Contacting your contacts
• A few people in your
network get a lot of calls
• Most people get few
calls
• If C = total number of contacts • So you will call 50% of your
• And f(n) = number of contacts called n times contacts once (n = 1)
• Then f(n) = C/(n*(n+1)) if n > 0 • 16.67% of them twice (n = 2)
• 8.33% of them 3 times (n = 3)
• etc
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24. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
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25. Habits...
Home Online Household Panel 1998-2001 (survey + time use diary)
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26. 'Calling practices'
• Qualitative study
• Lacohee & Anderson 2000 Interacting with the telephone, Int. J. Human-Computer
Studies (2000) 53, doi:10.1006/ijhcs.2000.0439
• “Participants reported that what they knew about the lives, habits, and routines of their friends
and family had an effect on when they might make calls. They not only declared themselves to be
differentially available at different times, they were also differentially available to different people
at different times, all of which modified their calling behaviour.”
• Call types
• Duty calls: generally to family members and were made because the caller felt a
sense of duty to keep in touch
• Maintenance calls: real motivation was to maintain a friendship
• Grapevine calls: passing on news, often prompted by a call
• Batch calls: making a series of outgoing calls
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27. Grapevine calls
Generally between family members but could involve circles of friends
One call (incoming) begets more (outgoing)
“My mum rang me to tell me that my cousin had just had a baby, she was premature
and there’d been all sorts of complications and things. I asked her about it but she’d
got the news from her sister, via my aunt, and she didn’t really know what was
happening so I telephoned my other cousin to find out what had really happened.”
− (Female participant in 2001 study)
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28. Batch calls
Batch calls are a collection of calls made at one sitting
Making a single call can prompt more calls to be made, even if it was not originally
intended
Other reasons: take advantage of cheap rate, boredom, loneliness
“When I picked up the telephone I was just going to make a quick call to my sister but
when we’d finished talking I rang three other people. It’s as though once I’ve put the
telephone down I think, who can I ring now?”
− (Female participant in 2001 study)
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29. Call groups: the algorithm
Two or more calls made or received in succession by the same subscriber
O → 140 secs → <begin group> O → 20 seconds → O → 30 seconds → I → 180 seconds
<end>
The “gap” value of 120 seconds can easily be changed
So:
Grapevine calls occur when the first call in a group is incoming, but the remainder are
outgoing: IOO...O but not OIO
Batch calls occur when all the calls in a group are outgoing: OOO but not OIOOO
Not all call groups fall into these two categories e.g. OOI
But: beware artefacts – e.g. modems and faxes (OOOOOOOOO) !!
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30. Group sizes...
• As you would expect...
• Many groups of a few calls, few groups of many calls
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31. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
Read the research @ cresi.essex.ac.uk Join the conversation @ cresi.wordpress.com
32. Batch calls
• Day 1 = Monday
• Day 7 = Sunday
• Clear cluster around 8 pm, goes on late
• Doesn't happen on Thursday & Friday?
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33. Grapevine calls
• Day 1 = Monday
• Day 7 = Sunday
• Clear cluster around 7 pm, stops at 11 pm
• Less likely on Thursday & Friday?
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34. People living alone aged < 56
• Day 1 = Monday
• Day 7 = Sunday
• Clear effect of 'work'
• Notice batch calls on Monday evening, Grapevines on Friday evening
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35. People living alone aged > 55
• Day 1 = Monday
• Day 7 = Sunday
• More day-time calling, especially batch calls
• 10 am (especially at weekends) and then evening for grapevine
• Saturday night?!
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36. Couple aged < 36, no children
• Day 1 = Monday
• Day 7 = Sunday
• Notice batch calls on Monday morning, Grapevines through the week
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37. Couple young children
• Day 1 = Monday
• Day 7 = Sunday
• Notice two waves of calling – 4-5pm, 7pm
• Notice batch calls in evenings, some grapevines may be children
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38. Couple older children
• Day 1 = Monday
• Day 7 = Sunday
• Notice again two waves of calling for grapevines – 4-5pm, 7pm
• Notice batch calls also after school
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39. Contents
• Practices - the view from here
• Practice Hunting
• Meet the data
• Contact 'practices'
• Identifying and quantifying 'practices'
• Practice patterns
• Final Thoughts
Read the research @ cresi.essex.ac.uk Join the conversation @ cresi.wordpress.com
40. Three questions that arise...
• If practices are distributed across space and time, how are they to be
defined and recognised?
• How do they develop, expand or retract in spatial and temporal scale?
• If practices emerge, persist and are reproduced and transformed over time
• How can such processes be detected and revealed, and at what scales?
• As present practices are shaped by practices and systems of practice from
the past
• How does this shaping work?
• How do present practices constitute institutions and infrastructures of
the future?
With apologies to: Researching Social Practice and Sustainability: puzzles and
challenges, SPRG Discussion Paper, 2011
Read the research @ cresi.essex.ac.uk Join the conversation @ cresi.wordpress.com
Editor's Notes
We’re going to focus in the main on the first question although we will present some examples for the second later and offer some suggestions for the third
Yeti -> Marks & Proxies
Examples of data - esp time-use to get at flows/profiles of practices. Emphasises ordering, differences between countries/cultures?
Green line = ‘mutual’ calls only: calls where at least 1 call in each direction between contacts (reciprocity) So cutting out all calls to/from contacts where the contact was only one-way helps a lot to make the distirbutions similar
But… At individual household level they don’t correlate And you can see the effect of filtering the contacts to be ‘mutual’ only
The K-S test suggests that the two distributions (survey and all contacts) are not the same. This is true in that the modal values (peaks) are different but the shapes are the same (?) Various possible reasons for this – underestimation in survey is very likely, may be missing household members in survey so summing contacts for these households will produce underestimation; calls/contacts may be generated by age < 16 who are not in survey so contacts are not 'counted'
Ignore lone parents & 'unrelated others' as n very small May confirm underestimation effect for households with non-surveyed children – couples with children aged 11-15, prediction (correlation) poor, better for hhs with older children who were in survey and thus their contacts were 'counted', best of all (as you would expect) for single persons