Técnicas y Herramientas
de Apoyo a la investigación (THA)
II. Técnicas de Investigación Cualitativa
Sesión 3. Análisis de
redes sociales
Alejandra Martínez
Monés
Noviembre 2009
2
Social network analysis
(SNA)
Considers relations and mutual effects of actors
within groups and organisations
–
Based on empirical data
–
Different levels of analysis (individual, sub-group,
community)
Formal methods, mainly based on graph theory and
graph algorithms
Fundamentals were presented as „Sociometry“
(Moreno, 1951)
–
Sociogram
–
Sociomatrix
Social network analysis
Social network
Set of
actors
(a person, a department, a company)
and
relationships
among them
Examples:
–
“is a friend of”
–
“is a neighbor of”
–
“distributes goods to”
–“is a member of”
Social Network Analysis
5
Social network analysis
Types of networks
Mode
–
One-mode networks: one set of actors
–
Two-mode networks: two sets of actors.
Affiliation networks: relationships between actors and
activities
Complete vs. egocentric networks
6
Application areas of SNA for computer
science
Human oriented disciplines
–
Computer supported collaborative learning (CSCL)
–Computer supported cooperative work (CSCW)
Network Analysis
–
Identification of bottlenecks in computer networks
–Fault-tolerance and –handling in distributed systems
Knowledge Structures
–
Growing interest in analysis of dynamic knowledge
structures, such as Wikipedia
7
Social network analysis
Some indicators
Centrality of actors
–
Degree based
–
Proximity / Closeness based
–
Betweenness based
Centralization of a network
Prestige of actors
–
Indegree and proximity
Groupings: Cliques, Clusters, Positions
8
Indicators - Examples
Individual:
–
Degree centrality: Activity of a node
C
D(n
i) = d(n
i) =
x
i+–
Normalized degree centrality
9
Indicators - Examples
Global:
–
Density: Global activity of the network
= 2 L / g (g -1) L, number of links;
g, number of nodes
–
Degree Centralization: Dependency of a single
actor
C
D=
1<=i<=g[C
D(n*) – C
D( n
i)] / (g-1) (g-2),
C
D(n*) = max
iC
D( n
i)
10
Social Network Analysis
Sociograms
Who is central in this
network?
SNA – visualisation techniques
Teacher
Group 1
Group 2
Group 3
Intra-group
Inter-group
= 24,45%
C
D= 63,6%
C
D(x00) = 81,9 %
C
D(x21) = 9,1 %
C
D(x32) = 9,1 %
Data Collection and Transformations
Computer-mediated communication
–
Discussion Forums
–Mailinglists
–
Web 2.0 applications, such as xing, facebook etc.
Archival records / artifacts
–
Bibliographies
–Wikis
–
Versioning systems (e.g. CVS)
Automatically processable
Potential for transformation between differenet
network types
13
Limitations of the method
Frequently not all of the interaction takes
place inside a computer environment
–
People going for a coffee and discussing their
homework
Interpretation is hard without „insider
knowledge“, i.e. replication is difficult
Combination with other methods is useful
„triangulation“
14
Indirect networks through
BSCW
(c)(MóvilBolsaImagenBibliotecaCentralization
Density
C
D= 68,21%
C
D=87,03%
= 35,48%
=17,54%
Final project Subproject 2Example – AO case study
15
SNA Software
UCINet – Whole Network Analysis
–
NetDraw – Visualization
–
http://www.analytictech.com/downloaduc6.htm
Pajek – Network Visualization (Large
Networks)
–
http://pajek.imfm.si/doku.php
SAMSA – SNA applied to CSCL scenarios
–
amartine@infor.uva.es
Teacher/ evaluator CSCL tool Interaction through the computer ParticipantsSAMSA
Interaction maps Configuration parameters Actions (Generic XML format) Event logsQUEST
Answers to questionnaires SNA indexes Sociograms Other SNA tools(UCINET NETDRAW) DL file
Sociometries
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SAMSA - Example
Raw source data (BSCW logfile)
User:[158009, 'stm1x06'] object:[162008, 'stm1x04_Diagrama_Estados'] Type:ReadEvent Time:1087083920.3 Members:[[158339, 'stm1x17', 'l5QcDnyhBmzkc'], [158099, 'stm1x09', 'SgBa8D7t4R3XQ'], [116766, 'stm1x00', 'Q5OG42nMsUCog'], ... Path: [[158012, ':stm1x06'], [156970, 'Ingeniería de software (03/04)'], [158541, 'El proyecto de la herramienta de encuestas'], [160233, 'Elaboración (primera iteración)'], [161426, '6. Diagramas de Estado']] On:[161426, '6. Diagramas de Estado'] Touched:[158012, ':stm1x06'] Icon:'/bscw_resources/icons/e_read.gif' Class:Document Content:application/pdfUser:[158249, 'stm1x14'] object:[161927, 'stm1-junio03.pdf'] Type:ReadEvent Time:1087134052.9 Members:[[158339, 'stm1x17', 'l5QcDnyhBmzkc'], [158099, 'stm1x09', 'SgBa8D7t4R3XQ'], [116766, 'stm1x00', 'Q5OG42nMsUCog'], [158129, 'stm1x10', 'kn/7H8eEIaSD6'], [157859, 'stm1x01', '8zEhF2Cl/XRlI'], [158399, 'stm1x19', '2GUzLTh.vkZNw'], [158009, 'stm1x06', '.MH/OmIqgz7HQ'], [158039, 'stm1x07', 'nhiUpoSQdFnWA'], [158249, 'stm1x14', 'bMckxPSGUQwts'], [158429, 'stm1x20', 'zpRVdxqaDKDkw'], [157979, 'stm1x05', 'qpE8BEv6DvK1M'], [158159, 'stm1x11', 'Ttibbr4C9YDdw'], [158309, 'stm1x16', 'gwkeGlWoNsn3Y'], [157949, 'stm1x04', 'ZbRd75nzzT39c'], [158219, 'stm1x13',
'dI/2GRyZPEbbI'], [158369, 'stm1x18', '1VpwTzrnjvteI'], [157919, 'stm1x03', 'JtWyaVVOJNo7E'], [158279, 'stm1x15', 'dE2Y.IRtuK30g'], [157889, 'stm1x02', 'xyAQS9GZf62Es'], [158069, 'stm1x08', 'wksiMtOrd/PK2'], [158189, 'stm1x12', 'RwmThVDSMhk0g']] Path:[[158252, ':stm1x14'], [156970, 'Ingeniería de software (03/04)'], [158473, 'Material académico'], [158531, 'exámenes']]
On:[158531, 'exámenes'] Touched:[158252, ':stm1x14'] Icon:'/bscw_resources/icons/e_read.gif' Class:Document Content:application/pdf
18
SAMSA - Example
XML “generic” format
<ACTIVITY id="SP1“ act-goal="Subproyecto 1"/> <SESSION date="09/10/2001"> <ACTION> <ACT.TIMESTAMP>08:42</ACT.TIMESTAMP> <ACT.SOURCE ref="laox38"/> <ACT.DESC> <ACT.IND> <ACT.IND.DOC type="ReadEvent"> <DOC key="47951" type="Note"> <DOC.PATH>:laox38</DOC.PATH> <DOC.PATH>Curso 2001-2002</DOC.PATH> <DOC.PATH>GENERAL'],[17938, ]</DOC.PATH> <DOC.PATH>Comentarios ... </DOC.PATH> <DOC.PATH>SERIA MAS ... </DOC.PATH> <DOC.CONTENT>None</DOC.CONTENT> </DOC> </ACT.IND.DOC> </ACT.IND> </ACT.DESC> </ACTION>
SAMSA - Example
Social Network (SAMSA output)
9 0 3 2 3 3 6 1 4 3 2 0 0 4 2 2 1 2 6 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 10 9 0 0 6 0 0 0 0 0 1 3 0 0 0 5 1 1 0 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 1 2 0 1 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 5 0 1 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 1 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 3 0 0 0 1 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 2 0 0 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 DL N=19
FORMAT = FULLMATRIX DIAGONAL PRESENT LABELS: x00 x21 x22 x23 x24 x25 x26 x27 x28 x29 x31 x32 x33 x34 x35 x36 x37
SAMSA - Example
SNA indexes (SAMSA output)
GRUPO OUTDEGREE INDEGREE OUTFARNESS INFARNESS OUTCLOSENES INCLOSENESS --- --- --- --- --- ---x00 44,00 3,00 55,00 101,00 32,73 17,82 x21 1,00 0,00 65,00 342,00 27,69 5,26 x22 25,00 8,00 72,00 100,00 25,00 18,00 x23 5,00 22,00 67,00 91,00 26,87 19,78 x24 3,00 3,00 77,00 113,00 23,38 15,93 x25 1,00 3,00 81,00 113,00 22,22 15,93 x26 0,00 16,00 342,00 69,00 5,26 26,09 x27 3,00 1,00 77,00 113,00 23,38 15,93 x28 2,00 4,00 79,00 113,00 22,78 15,93 x29 1,00 6,00 70,00 108,00 25,71 16,67 x31 0,00 2,00 342,00 97,00 5,26 18,56 Densidad normalizada: 14,33 % Densidad: 29,53 % La centralizacion(InDegree): 97,84 % La centralizacion(OutDegree): 226,85 %
