The Network Structure of Sociology Production

1
The Network Structure of Sociology Production
James Moody Ohio State University Indiana
University December, 2005
2
Introduction

• Outline
• Big Picture Networks, Structure, Action
  Outcomes
• Guiding Questions General Approach
• Examples Hierarchy, Romance the spread of STDs
• Networks Science Two Questions 4 networks
• How do scientific fields evolve?
• Where do good ideas come from?
• Data Sources Methods
• Results
• Where does sociology fit? Journal co-citation
  networks
• What do sociologists study? Topic networks
• Who produces sociology? Social science
  collaboration networks
• Discussion

3
Networks, Structure, Action Outcomes
Guiding Questions
Where does social structure come from? How does
social structure enable constrain action
outcomes? General Approach (1) Seek structure
in patterns of association
To speak of social life is to speak of the
association between people their associating in
work and in play, in love and in war, to trade or
to worship, to help or to hinder. It is in the
social relations men establish that their
interests find expression and their desires
become realized. Peter M. Blau Exchange and
Power in Social Life, 1964
4
Networks, Structure, Action Outcomes
Guiding Questions
Where does social structure come from? How does
social structure enable constrain action
outcomes? General Approach (2) Focus on
large-scale network structure
"If we ever get to the point of charting a whole
city or a whole nation, we would have a picture
of a vast solar system of intangible structures,
powerfully influencing conduct, as gravitation
does in space. Such an invisible structure
underlies society and has its influence in
determining the conduct of society as a whole."
J.L. Moreno, New York Times, April 13, 1933
5
Networks, Structure, Action Outcomes
Guiding Questions
Where does social structure come from? How does
social structure enable constrain action
outcomes? General Approach (3) Link
well-defined network structures to relevant
social theory
The social structure of the dyad rests
immediately on the one and on the other of the
two, and the secession of either would destroy
the whole. . . . As soon, however, as there is a
sociation of three, a group continues to exist
even in case one of the members drops
out. Simmel (1908 1950123)
This can then be operationalized as
node-connectivity directly.
6
Networks, Structure, Action Outcomes
Guiding Questions
Where does social structure come from? How does
social structure enable constrain action
outcomes? General Approach (4) in a manner
that can explain truly emergent social properties.
Social facts assume a shape, a tangible form
peculiar to them and constitute a reality sui
generis vastly distinct from the individual facts
which manifest that reality Durkheim
Rules Of Sociological Method
7
Networks, Structure, Action Outcomes
Examples Hierarchy in High School
A Gallery of Friendship Networks
776 adolescents from a working-class, all-white,
suburban, school in the Midwest.
(Source Add Health)
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Networks, Structure, Action Outcomes
Examples Hierarchy in High School
A Gallery of Friendship Networks
678 adolescents from a working-class, all-white,
rural, school in the Midwest.
Across these settings (and many more) we can
literally see the differences imposed by classic
Blau space features of youth communities.
Race, grades, SES etc. often shape the gross
topography of school friendship networks.
(Source Add Health)
9
Networks, Structure, Action Outcomes
Examples Hierarchy in High School
Distribution of Popularity
Size
Community type
By size and city type
10
Networks, Structure, Action Outcomes
Examples Hierarchy in High School
For the 129 Add Health school networks, the
observed distribution of the hierarchy test
statistic (tau) for various models is
Suggesting that the ranked-cluster models beat
random chance in all schools.
11
Networks, Structure, Action Outcomes

• If you examine all schools you find
• All of the school networks have a rank-strata
  structure
• The structure remains constant even though
  nearly half of all relationships are new
• Peoples position in the popularity distribution
  is fluid
• What social process will explain a stable
  macro-structure in the face of dynamic relations?

12
Networks, Structure, Action Outcomes
Examples Hierarchy in High School
Endogenous Building Blocks A periodic table of
social elements
(0)
(1)
(2)
(3)
(4)
(5)
(6)
003
012
102
111D
201
210
300
021D
111U
120D
021U
030T
120U
021C
030C
120C
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Networks, Structure, Action Outcomes
Examples Hierarchy in High School

• Classic balance theory offers a set of simple
  local rules for relational change
• A friend of a friend is a friend
• My enemys enemy is my friend.

(0)
(1)
(2)
(3)
(4)
(5)
(6)
003
012
102
111D
201
210
300
021D
111U
120D
021U
030T
120U
021C
030C
120C
14
Networks, Structure, Action Outcomes
Examples Hierarchy in High School
030C
120C
102
111U
021C
201
012
111D
300
003
210
021D
120U
030T
021U
120D
(some transitions will both increase transitivity
decrease intransitivity the effects are
independent they are colored here for net
balance)
15
Networks, Structure, Action Outcomes
Examples Hierarchy in High School
ERGM Coefficient Distributions
0.8
Endogenous
Focal Orgs.
Dyadic Similarity/Distance.
0.6
0.4
0.2
0
-0.2
-0.4
-0.6
GPA
SES
Fight
College
Drinking
Same Sex
Same Race
Both Smoke
Same Clubs
Same Grade
Coefficients based on pseudo-likelihood
approximations, here standardized so they fit
well on the page
16
Networks, Structure, Action Outcomes
Examples Building Romantic Networks
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Networks, Structure, Action Outcomes
Examples Building Romantic Networks
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Networks, Structure, Action Outcomes
Examples Building Romantic Networks
What micro-structures are taboo in high-school
romantic relations?
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Networks, Structure, Action Outcomes
Examples Building Romantic Networks
The 4-cycle prohibition fits the observed data.
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Networks, Structure, Action Outcomes
Examples Systemic Effects of Local Action in STD
Cores

• An STD Puzzle
• contact rates are low (most people have few
  partners)
• dyadic transmission is difficult (compared, say,
  to the flu)
• people are infectious for short periods of time
• Particularly for bacterial STDs, but even AIDS
  infectiousness peaks shortly after acquiring the
  disease
• How does the disease manage to remain endemic?
• Activity heterogeneity is the common answer a
  few active stars keep the disease endemic
• But this doesnt fit the empirical
  facts-on-the-ground in many cases.
• What if many people make small changes, instead
  of few people making big changes?

21
Networks, Structure, Action Outcomes
Examples Systemic Effects of Local Action in STD
Cores
22
Networks, Structure, Action Outcomes
Examples Systemic Effects of Local Action in STD
Cores
23
Networks, Structure, Action Outcomes

• While my substantive work has ranged widely, I
  always focus on the intersection of individual
  action embedded in network structures over time.
• The long-term goal is to identify fundamental
  principles for either networks or action that can
  explain the wide variety observed social
  structures with a small number of locally
  digestible and contextually relevant action
  rules.
• My new work turns these tools to questions about
  the development of science.

24
Networks Science Two Questions 4 networks
"Science, carved up into a host of detailed
studies that have no link with one another, no
longer forms a solid whole." Durkheim, 1933
25
Networks Science Two Questions 4 networks

• The extent to which science is carved up into a
  host of detailed studies that have no link with
  one another is a question of network cohesion
• A fractured discipline will be dominated by tight
  clusters based on specific research problems,
  while an integrated discipline will have strong
  connections bridging research problems.

26
Networks Science Two Questions 4 networks

• How do scientific fields evolve?
• Is there a coherent logic to the ebb and flow of
  topics studied?
• How does the success or failure of ideas depend
  on the social community in which it is embedded?
• (How) Does the evidentiary basis of a field shape
  its logic of discovery?
• The descriptive answer is given by mapping the
  field in network space.
• The analytic answer will come by modeling the
  emergence, growth and decline of scientific
  subfields.

27
Networks Science Two Questions 4 networks

• 2) Where do good ideas come from?
• What is a good idea?
• Ideas that change a scientific field. Indexed by
  (a) citations and (b) the relevant topography of
  the networks within which the idea was originally
  embedded. Ideas are not inherently good they are
  recognized as good by their effect on a field.
• How do disciplines produce new ideas?
• Intersection ? Good ideas are produced by
  combining ideas of others in unique ways (Burt)
• Development ? Good ideas arise naturally from
  either the progressive error reduction process
  of good normal science (Popper) or the accepted
  practices of a scientific community (Crane).
• Peer Influence Recognition ? Any idea is a
  good idea if others think so, and thinking so is
  influenced by the network. (Gould).
• Resource competition ? Search for prestige
  conditioned by organizational structure (Fuchs)
• Will model this by examining how citations are
  affected by field dynamics (and vice versa).

28
Networks Science Two Questions 4
networks Theoretical approaches to scientific
development

• Normal Science, accumulation revolution
• Science is problem driven evidence based
• Consensus emerges through a competition of ideas
  against data
• (though lab ethnography repeatedly shows that
  consensus is often more socially constructed than
  evidentiary)
• Scientific Star systems reward prior success,
  and stars shape research agendas
• Boundary Specification Science as a profession
• -Motivated by prestige competition for
  resources
• -Competition will lead to both vanquishing and
  niche filling
• Disciplinary identity coherence become a key
  issue
• Contested fields lead to chaotic outcomes
  (Abbott 2001)

29
Networks Science Two Questions 4
networks Theoretical approaches to scientific
development

• Invisible Colleges
• Informal communities create acceptable scientific
  standards
• Boundaries are defined socially through
  interaction
• Scientific (social) Movements
• Combination of many of these ideas under a social
  movement frame
• Coherence becomes a framing grievance issue
  used to shape resource allocation

30
Networks Science Two Questions 4
networks Theoretical approaches to scientific
development
We are thus left with multiple action frames to
guide our understanding Truth Ideas run their
error-reduction course (Popper) Prestige Actors
seek the greatest visibility (Merton) Resource
competition To the victor goes the spoils
Fuchs Boundary Protection ( Lamont) Fractal
Development (Abbott) Community Influence (SSK
Collins, etc) Peer magnification (Gould) Power
(JL Martin) For entire fields, these mechanisms
are largely unknown and underspecified. ? Need
to extend beyond particular lab studies ? Take a
large-scale Satellite view of science
dynamics ? Link action frames to specific
patterns in 4 science networks
31
Networks Science Two Questions 4
networks Theoretical approaches to scientific
development

• Four relevant networks
• Citation networks a direct trace of scientific
  recognition production
• Topic networks clusters of scientific products
  related to the same subject
• Collaboration networks invisible communities
  of social interaction that produces scientific
  products
• Research Communities People linked through
  common research topics (Substantively a
  derivative of 2 3)

32
Networks Science Two Questions 4 networks
Scientific Environments
Evidentiary Basis How do we array disciplines
with respect to evidence? Two Dimensions
Objectivity Control Objectivity is taken from
Popper The extent to which a given knowledge
claim is independent of the knower. Control
refers to the ability of scientists to directly
manipulate the object of study. Lab Science
with complete ability to control apparatus (and
thus environment) represents the strongest
ability, while observation represents the
other. Cases Chemistry (Lab Science High
Objectivity High Control) Geology (Field
Science High Objectivity Low
Control) Sociology (Social Science Moderate
Objectivity Low Control) Literary Criticism
(Humanities Low Objectivity Low
Control) This approach is very similar to Fuchs
(1993)
33
Networks Science Two Questions 4 networks
Chemistry Geology Sociology Literary Criticism
Citation Journal Citation Structure
Topics Subfield Evolution
Collaboration Collaboration Cohesion
Community
34
Networks Science Two Questions 4
networks Focusing on Sociology as a current case

• The field of sociology can thus be thought of as
  the intersection of multiple networks.
• The shape of these networks differs across scales
  and over time.
• - Differences between local and global visions
  of the network shape our perceptions of
  scientific coherence.
• We tend to perceive coherence in our own
  specialty fields and incoherence for the entire
  discipline.
• A globally federated structure, that cannot
  easily exclude empirical topics, might still be
  socially coherent if scientific mixing cross-cuts
  empirical problems.
• We can see this structure by examining these 4
  networks at large scale and over time.

35
Data Sources

• Citation Networks
• Compiled from the ISI web of science Journal
  citation tables
• Covers 1681 social science journals indexed in
  2003
• Will eventually
• -fill this series from 1990 to present across all
  fields.
• -Add a sample of paper-level citations to model
  performance.
• Topic Collaboration Networks (for Sociology)
• Compiled from Sociological Abstracts
• 281,163 papers published between 1963 and 1999
• A sub-sample of sociology only papers published
  in a select set of non-specialty sociology
  journals ? 35 of the total (100K)
• Contains information on title, abstract,
  keywords, author(s), tables, journal citation
• Will use similar indexes for Chemistry, Geology
  and Lit Crit

36
Where does sociology fit?

• Perennial debates over the existence of a
  theoretical core
• Rapid growth in the internal diversity of topics
  sociologist study

37
Where does sociology fit?

• Perennial debates over the existence of a
  theoretical core
• Rapid growth in the number of journals relevant
  to sociologists

38
Where does sociology fit?

• This growth diversity has been seen as evidence
  for the ultimate emptiness of sociology as a
  scientific discipline.
• But disciplines are shaped by the connections
  between ideas, not the number of ideas.
• That is, we recognize fields by who they speak to
  as much as by what they speak about.
• The clearest empirical trace of this
  communication is citation.
• Disciplines can then be defined as clusters of
  work that speak more to each other than to anyone
  else, which we trace with co-citation networks.

39
Where does sociology fit?
Building co-citation networks
Links in a co-citation network are constructed by
measuring how similar each journal is to every
other journal. Similarity is gauged by
correlating the pattern of citations received by
each journals from every other journal.
Comparing across columns tells us whether the two
journals are recognized by others as similar.
40
Where does sociology fit?
Building co-citation networks
AJS ASR AER JER AJS ASR
AER . . . JER
Links in a co-citation network are constructed by
measuring how similar each journal is to every
other journal. Similarity is gauged by
correlating the pattern of citations received by
each journals from every other journal.
1.0
High
1.0
1.0
Med
Low
High
Low
Low
1.0
This create a valued network of ties between two
journals. I use a cosine similarity score
developed in bibliometrics, selected for those
with ties gt 0.45 at sharing at least 2 of
their citation volume. Source Loet Leydesdorff
41
Where does sociology fit?
Economics co-citation similarity network
Density 0.197 N152 Isolates (not shown) 5
Node size proportional to log(degree)
42
Where does sociology fit?
Political Science co-citation similarity network
Density 0.160 N69 Isolates (not shown) 10
Node size proportional to log(degree)
43
Where does sociology fit?
Sociology co-citation similarity network
Density 0.140 N69 Isolates 7
44
Where does sociology fit?
45
Where does sociology fit?
46
Where does sociology fit?
47
Where does sociology fit?

• Sociology fits at the center of the social
  sciences. We are not as internally cohesive as
  Economics or Law, but more so than many
  (anthropology, allied health fields).
• This represents a tradeoff. We have traded
  unique dominance of a topic (markets, politics,
  mind, space, history) for diversity thus
  centrality.
• Sociology is an interstitial discipline (Abbott,
  2004) in at least two-senses
• There is no content topic we can reasonably
  exclude
• We pull together, and generate, the ideas and
  topics covered by specialty disciplines.
• This makes us uniquely positioned to provide
  insights on many different empirical questions.
  How have the topics sociologists study shifted
  over time?

48
What do sociologists study?

• How do we capture the internal organization of
  research problems?
• Could use paper-level citation networks (see
  Hargens 2000), but data are difficult expensive
  to obtain for large-scale networks.
• Can examine the network of papers formed by the
  topics they write about.
• Directly taps scientific content
• Purely endogenous creation of topics that allows
  new topic areas to emerge and old ones to die
  over time
• Tractability data can be extracted from
  information held in Sociological Abstracts
• Multiple levels
• Coarse grained? Focus solely on keywords (Light
  2005)
• Fine grained ? Use all information available
  (title, abstract, keywords)

49
What do sociologists study?
A fine grained view

• Data Selection Manipulation
• Index entries contain title, abstract and
  keywords that summarize the papers content.
• Sample all papers indexed within four 3-year
  windows between 1970 and 1999.
• Construct a paper by word matrix, where the
  ij cell lists how many times word i is used to
  describe paper j.
• Word set is stemmed to get at root words
• A stop-list is used to minimize inclusion of
  low-information content words (the and is
  etc.) or words commonly found in the data source
  (Tables Figure References)
• Construct a network by linking the most highly
  correlated papers
• Use correlation of 0.40 or better
• Ties are treated as valued in the network analyses

50
What do sociologists study?
A fine grained view

• Analysis Presentation General approach is
  quantitatively inductive
• - Construct a low-dimensional map of the network,
  using contour sociograms. These allow for full
  information in the network structure.
• Use cluster analysis to identify distinct topics
• Use a variant of Moodys RNM algorithm to cluster
  the network
• This clustering routine
• (a) is efficient Allows clustering on 10s of
  thousands of nodes
• (b) automatically specifies the optimal number
  of clusters
• (c) allows that some cases can fall between
  clusters
• I set a minimum cluster size of 12 papers
  published over the 3-year window.
• Evaluate the clustered papers for content and
  label the maps.

51
What do sociologists study?
A fine grained view
Analysis Presentation General approach is
quantitatively inductive Compare the maps over
time qualitatively, looking for general changes
in the frequency alliance of topics. Examine
shifts in structural indicators of the extent of
clustering cluster size distributions.
52
What do sociologists study?
A fine grained view
Example One-step neighborhood of More
information, better jobs?
53
What do sociologists study?
A fine grained view
Example One-step neighborhood of More
information, better jobs?
54
What do sociologists study?
A fine grained view Content (all journals)
55
What do sociologists study?
A fine grained view Content (all journals)
56
What do sociologists study?
A fine grained view Content (all journals)
57
What do sociologists study?
A fine grained view Content (all journals)
58
What do sociologists study?
A fine grained view Content (all journals)

• The cluster content of the topic network has
  evolved slowly
• Some clearly central specialties have remained
  prominent over the entire period. This includes
  larger areas such as
• Class Stratification
• Race Ethnicity
• Education
• Gender (Strongest from 1980s on)
• Family (Strongest from the 1980s on)
• Crime
• As well as clearly distinct, though numerically
  smaller bodies of research related to
• Suicide
• Sociology of Science, Technology Reflexive
  sociology
• Unions

59
What do sociologists study?
A fine grained view Content (all journals)

• The cluster content of the topic network has
  evolved slowly
• The clearest change has been the rapid growth of
  social research on health.
• Dominated by a very large body of research
  related to HIV/AIDS
• Other areas of relative growth include
• Family topics were most prominent in the 1980s
• A strong presence of research on sex sexuality
  emerged in the 1980s and 90s
• Relative declines have come in areas such as
• Groups
• Interaction
• Radical studies
• Elite studies
• Summary A move away from basic social processes
  toward studying social problems, with a growing
  uniqueness of theory method

60
What do sociologists study?
A fine grained view (all journals)
Cluster Size Distribution
(hidden)
61
What do sociologists study?
A fine grained view Content (Restricted Sample)
62
What do sociologists study?
A fine grained view Content (Restricted Sample)
63
What do sociologists study?
A fine grained view Content (Restricted Sample)
64
What do sociologists study?
A fine grained view Content (Restricted Sample)
65
What do sociologists study?
A fine grained view Content (Restricted Sample)

• The cluster content of the restricted topic
  network has evolved similarly to the wider social
  science field
• The subfield structure is less dominated by the
  purely applied work on HIV/AIDS in the 90s, but
  there is a still a clear association of topics
  around sexuality, health and AIDS.
• Health, Family, Education, Gender, and Race are
  always prominent and large.
• The relative prominence of reflexive sociology
  is much higher
• These topics cannot be published elsewhere, and
  the resulting tight cluster looks proportionately
  larger in the smaller sample.

66
What do sociologists study?
A fine grained view (Core Soc journals)
Cluster Size Distribution
Hidden
67
What do sociologists study?
A fine grained view Content
We can measure the degree of consensus in words
used to describe papers with
C S pi2
Where pi is the proportion of times word i is used
68
What do sociologists study?
A fine grained view Content
Word Consensus Scores 1970 - 1999
Soc Only
C (x 100)
All SA Journals
69
What do sociologists study?
A fine grained view (Core Soc)
Proportion of papers falling inside a cluster
Total
Cn gt 12
Restricted
Total
Cn gt 100
Restricted
70
What do sociologists study?
A fine grained view (Core Soc journals)

• Largest Clusters
• 1970
• Culture (126,3.7)
• Organizations (134,4.0)
• Race (Black) (137,4.1)
• Students (137,4.1)
• Community (138,4.1)
• 1980
• Education (167,2.6)
• Sex Roles (182,2.9)
• Research (191,3.1)
• Sociology (225,3.6)
• Family (273,4.3)

• 1990
• Women (246,2.7)
• Schools (259,2.8)
• Sociology (427,3.6)
• Health (427,4.65)
• Family (273,4.3)
• 1997
• Children (302, 2.89)
• Women (346, 3.32)
• Critical Sociology (359, 3.32)
• Education (380, 3.64)
• Health (714, 6.8)

Hidden
71
What do sociologists study?
A fine grained view
We can measure the extent that ties fall within
clusters with the modularity score
Where s indexes clusters in the network ls is
the number of lines in cluster s ds is the sum
of the degrees of s L is the total number of
lines
72
What do sociologists study?
A fine grained view
Network Modularity 1970 - 1999
All SA Journals
Soc Only
Modularity Score
73
What do sociologists study?
A fine grained view
Proportion of all ties within cluster 1970 - 1999
In-cluster ties / Total ties
All Journals
Soc Only
Hidden
74
What do sociologists study?
A fine grained view
Number of Clusters 1970 - 1999
All Journals
In-cluster ties / Total ties
Soc Only
75
What do sociologists study?
A fine grained view
Mean Cluster Size 1970 - 1999
All Journals
Soc Only
In-cluster ties / Total ties
76
What do sociologists study?
A fine grained view

• The cluster structure of the topic network
• The vast majority of papers can be assigned to
  clear clusters, with slight growth in this
  proportion over time.
• The number of clusters has increased rapidly,
  though slightly slower within core sociology than
  in the broader field of social science.
• There has been significant growth in the tails of
  the distribution the size distribution is more
  skewed in later periods.
• The modularity of the network has increased over
  time, though most of this change is between the
  1970 and 1980 periods.

77
What do sociologists study?
A fine grained view

• Next steps
• Build a continuous moving window to fill in the
  dates from 1970 to 2005.
• Link clusters across time periods, so we can
  track exactly the relative growth and decline of
  each subfield.
• Model this growth as a function of connections to
  other fields, author composition and disciplinary
  environment.
• Build this networks dual Scientists connected
  through topics.

78
What do sociologists study?

• A clustered topic structure focused strongly on
  practical problem solving has a hint of
  Durkheims concern Is there any integration
  across these topic clusters?
• We shouldnt jump too quickly to the fractured
  conclusion
• Topic clusters are formed from papers, and papers
  typically have well encapsulated ideas. They
  have a small maximum digestible unit
• Scientific integration is really about how
  scientists bridge these multiple topics.
• If authors write and collaborate across these
  topics then, ideas can quickly disseminate as
  well.
• What is the structure of the collaboration graph
  if this is highly clustered it would signal
  potential fragmentation ? Who produces sociology?

79
Who produces sociology?

• Science is typically produced through
  collaboration, both formally and informally
  (Crane 1972, Crane Small 2000, Friedkin 1998).
• The best empirical trace of collaboration for
  large communities of science is coauthorship.
• Misses the less intense collaborations recognized
  in acknowledgements, discussions, colleagues
  reading each others work
• But should provide the strongest test of a
  fractionalization hypothesis, since the set of
  people we write with should be more like us than
  the set of people we have lunch with or discuss
  work with informally.
• There are differences across subfields in formal
  collaboration rates, which, if anything, should
  magnify the extent of observed fragmentation.

80
Who produces sociology?
Coauthorship Trends in Sociology Sociological
Abstracts and ASR
0.75
0.6
0.45
Proportion of papers with gt1 author
0.3
Sociological Abstracts
ASR
0.15
0
1930
1940
1950
1960
1970
1980
1990
2000
Year
81
Who produces sociology?
Distribution of Coauthorship Across
Journals Sociological Abstracts, 1963-1999
Child Development
1
0.8
Soc. Forces
J. Health Soc. Beh.
ASR
0.6
Proportion of papers w. gt1 author
AJS
J.Am. Statistical A.
0.4
Atca Politica
Soc. Theory
Signs
0.2
J. Soc. History
0
0
100
200
300
400
500
600
700
800
900
1000
1100
Coauthorship Rank
82
Who produces sociology?
83
Who produces sociology?
Construct a collaboration network by assigning an
edge between any pair of people who coauthored a
paper together.
Example Paths 3-steps from Stan Wasserman
N361
84
Who produces sociology?
Construct a collaboration network by assigning an
edge between any pair of people who coauthored a
paper together.
Example Paths 3-steps from Stan Wasserman
N361
Node size proportional to log of degree
85
Who produces sociology?
The simplest summary test for a fragmented
network is to measure the extent of clustering in
the network. Watts work on the small-world
problem suggests that if the collaboration
network is a small world network it might be
fractured.
CLarge, L is Small SW Graphs

• High relative probability that a nodes contacts
  are connected to each other.
• Small relative average distance between nodes

86
Who produces sociology?
In a highly clustered, ordered network, a single
random connection will create a shortcut that
lowers L dramatically
Watts demonstrates that Small world properties
can occur in graphs with a surprisingly small
number of shortcuts
87
Who produces sociology?
Locally clustered graphs are a good model for
coauthorship when there are many authors on a
paper.
Paper 1
Paper 2
Paper 3
Paper 4
Paper 5
Newman (2001) finds that coauthorship among
natural scientists fits a small world model.
I test this model on the sociology coauthorship
network, using all authors from 1963 1999.
88
Who produces sociology?
Observed
Random
Clustering
0.194
0.206
9.81
7.57
Distance
The sociology network is less clustered than
would be expected by chance and somewhat longer
overall distances. This suggests that it does
not have a small-world structure.
89
Who produces sociology?
The network has a broad Core-periphery structure
(68,923)
59,866
38,823
29,462 Bicomponent
Component
Unconnected
Structurally Isolated
90
Who produces sociology?
Largest Bicomponent, g 29,462
91
Who produces sociology?
Internal Structure of the Coauthorship Core
Health
General Sociology
92
Who produces sociology?
93
Who produces sociology?
Internal Structure of the largest bicomponent
Group 1
Group 2
Size
3667
987
In-group / out- group ties
3.24
2.86
male
67
52
Years in discipline
8.46
4.67
Number of co-authored publications
5.32
3.24
94
Who produces sociology?
Internal Structure of the largest bicomponent
95
Who produces sociology?
96
Who produces sociology?

• Strong specialty effects for ever-coauthored
• Unlikely
• History Theory
• Sociology of Knowledge
• Radical / Marxist Sociology
• Feminist / Gender Studies
• Likely
• Social psychology
• Family
• Health Medicine
• Social Problems
• Social Welfare

97
Who produces sociology?

• Weak specialty effects for network embeddedness
• Large number of coauthors increases embeddedness
• Large number of people on any given paper
  decreases embeddedness

98
Who produces sociology?
Graph Connectivity, Cumulative 1963 - 1999
0.6
in Giant Component
0.5
0.4
of connected in bicomponent
Percent
0.3
0.2
0.1
0
1965
1970
1975
1980
1985
1990
1995
2000
Years (1963 - date)
99
Who produces sociology?
0.4
2.25
Evolution of Network Cohesion 5-year moving
window
0.35
2.2
0.3
0.25
2.15
0.2
Percent
Connectivity
2.1
0.15
0.1
Connectivity
2.05
Bicomponent
0.05
Component
0
2
1975
1980
1985
1990
1995
2000
Year
100
Summary discussion

• Social Science Citation Structure
• Economics, Law, Psychology, Business/Management,
  Linguistics are most cohesive
• The are also peripheral in that they speak to a
  relatively limited set of problems
• Sociology is at least as cohesive as Political
  Science, and more cohesive than fields such as
  Anthropology, Social Work, Education or allied
  health fields that all have more limited
  empirical domains
• Our position represents a tradeoff between
  internal cohesion and external centrality.

101
Summary discussion

• Scientific Topic Network
• Big-Picture A general progression towards
  problem solving and the specialization of work on
  theory methods (Light 2005).
• Fine-grained structure
• A federated topic structure that has remained
  largely constant since the 1970s, though there
  have been shifts in topics.
• Key content areas have remained largely constant
• Race, Family, Class, Gender, Science, and Health
• A decrease in focus on general foundation
  problems
• Group structure, community, interaction
• An increase in work on social problems
• Health HIV/AIDS -related topics
• Some evidence for greater homogeneity in topics
  discussed

102
Summary discussion

• Scientific Collaboration Network
• The networks is not divided into small
  research-area based clusters.
• There is no partition that strongly separates
  scientists.
• This has to imply that authors bridge topic
  clusters.
• This is good for social cohesion, and probably
  good for theoretical cohesion.
• Caveat There is evidence for a division based
  on research method, with largely quantitative
  work more likely to be coauthored, though there
  is no such simple division in the topics network.

103
Summary discussion

• Combined, these models suggest a discipline that
  is integrated socially and locally cohesive
  topically.
• Discipline-wide integration will likely only
  increase as pressures for collaboration push more
  scientists to work together across topics.
• However, the perception of disintegration will
  likely continue
• because most of us are only exposed outside our
  areas by work that appears in the general
  journals.
• But almost all of the topical cohesion is due to
  normal science work occurring in specialty
  journals.

104
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