Social Networks, Travel Behavior, Social Capital

Edward Pultar

Department of Geography, University of California, Santa Barbara

Advisors: Martin Raubal, Michael F. Goodchild, Kostas Goulias, Stephan Winter

Introduction • We have become a mobile information society"• Modern, internet-based social networks allow

us to connect with large, dispersed structures"• Need for understanding spatial behavior for

travel with information from a social network"• Case study: web-based networks that provide

free lodging with locals"

Research Questions • How does a personʼs access to an Internet-

based social network influence spatial behavior?"

• What differences in spatial behavior are exhibited when utilizing a novel amalgamation of social, transportation, and data communication networks?"

• How can these network levels be visualized efficiently for use as a decision support tool for mobile travelers?"

Related Work • Social networks and mobile hospitality

(Molz 2007) • Social networks and gender (Hjorth and

Kim 2005) or religion (Nyland and Near 2007)

• Virtual and physical location-based social networks (Pultar and Raubal 2009)

• Trust and reputation (Lauterbach et al. 2009; Bialski and Batorski 2007)

• Time geography (Hägerstand 1970, Raubal et al. 2007)

Methodological Approach

• CouchSurfing social network utilized in this research [ www.couchsurfing.org ]"

• Members find each other using a search tool"• Trust network of references"• Over 2.5 million users in 2011"• Travel integrates social networks,

transportation networks, and data networks"• Contemporary, emerging form of connection"

What is CouchSurfing? •  Users make decisions of who to contact utilizing a

modern social network"  Profile"  Connections"

•  Members contact each other using data networks"  Internet e-mail"  SMS"

•  Transportation networks allow members to move from virtual to physical environments"  Plane"  Train"  Bus"

What is CouchSurfing?

What is CouchSurfing?

Social Capital • Social networks utilizing physical and virtual

location requirements lead to changes in spatial behavior"  Physical: face-to-face presence"  Virtual: Internet-based"

• How do we measure an individualʼs social capital in a network based on physical and virtual components?"

Social Capital Questions • How is an individual’s social network capital

represented in a setting combining physical and virtual spaces?

• How do geographical distances influence measures of social capital?

• How can different roles of a member in a social network affect social capital?

Social Capital Literature •  Interaction between Information and

Communication Technologies (ICT) and human travel behavior (Kwan et al. 2007)

•  Location-based services (LBS) and affordances with time geography for individual preferences (Raubal et al. 2004)

•  Social capital definitions •  Resource (Bourdieu 1983) •  Process (Putnam et al. 1993) •  Limitations of exclusively economic approach (Portes

and Landolt 2000) •  Ongoing debate and evolution (Fulkerson and

Thompson 2008) •  Evolutionary psychology (Kanazawa and Savage 2009)

Capital Measures •  Social capital means different things to

different people • Generally social capital has an effect on a

person or group’s abilities and a higher amount of social capital increases their productivity

• With an egocentric approach a greater number of connections means more social capital

Ct =Nl (Equation 1) where Ct is the total measure of an individual’s social capital

as defined by Nl, the number of links or connections an individual has

Capital Measures • CouchSurfing (CS) network as a case study

where members have different roles •  Host •  Guest

• Geographically spread network

Ct =αCg +βCh (Equation 2) where Cg is social capital measured by how many guests

an individual has had and the proximity of each guest. Ch is the similar measure but with hosting. Weights α and β put more influence on having guests or having hosts with α + β = 1

Capital Measures

(Equation 3)

Ng = Number of guests individual has had for given time interval Dg = Distance function to find distance of guest i from individual

(Equation 4)

Nh = Number of hosts an individual has had for given time interval Dh = Distance function to find distance of host j from individual

€

Cg = [Dg (i=0

i=Ng

∑ i)]12

€

Ch = [Dh(j=0

j=Nh

∑ j)]12

Capital Measures • Geography influences social capital • Distance

•  Any units •  International borders •  Combination or other geographical measures

• Objective measure of social capital •  An individual’s role in the network •  Distance between members •  Allows for better matching of members •  Integrates experience and trustworthiness from

histories

Spatio-temporal Geovis

Figure 1. Spatio-temporal geovisualization of CouchSurfer A’s hosting and traveling: home location is black, host activities are green and guest activities are red.

Spatio-temporal Geovis

Figure 2. Spatio-temporal geovisualization of CouchSurfer B’s hosting and traveling: home location is black, host activities are green and guest activities are red.

Time Geography •  People and resources are available at a limited

number of locations for a limited amount of time •  Space-time paths depict the movement of

individuals in space over time •  Time geography defines the space-time

mechanics of location presence by considering different constraints (Hägerstrand 1970)   Authority   Capability   Coupling

http://www.gisblog.net/

Time geography with multi-network travel behavior

Sample Time-Geographic Concepts

Multi-Network Traveler Examples

Authority constraints Host provides guest with operating hours of sites in addition to a sequence in which to visit.

Capability constraints Host shares local and international transportation capabilities as well as the current status.

Coupling constraints Initial corporeal meeting between guest and host; also synchronicity between a traveler and any mode of transportation.

Fixed vs. flexible activities Traveler wants to mountain climb with flexible locations and schedule versus traveler designating a fixed activity location such as visiting the Louvre.

Potential path areas and prisms These are created using a traveler’s desired travel destinations in a specified duration of time.

Space-time stations Various tourist activities such as a historic church or a host’s residence are space-time stations.

Time Geography & Geovisualization

Figure 2. Space-time paths of host (blue), guest (red), and both host and guest (green).

Conclusions & Future Work • Computational and geovisualization

frameworks for location-based social network capital

•  Emphasis on importance of geography and space in social capital

•  Influence of different roles for individuals in social networks

Conclusions & Future Work •  Survey of expert users points towards

hosting role being more important • More interviews of members to find α and β

weights •  Time geography with multi-network travel

behavior •  Software tools for 3-D time geography

combining a variety of networks

References Bialski, P and Batorski, D, 2007, Trust Networks: Analyzing the Structure and Function of Trust.

International Network of Social Network Analysis SUNBELT Conference, Corfu, Greece. May, 2007.

Bourdieu P, 1983, The Forms of Capital. In: JG Richardson (ed), The Handbook for Theory: Research for the Sociology of Education. Greenwood Press, New York, 241-258.

Fulkerson GM and Thompson GH, 2008, The Evolution of a Contested Concept: A Meta-Analysis of Social Capital Definitions and Trends (1988-2006). Sociological Inquiry, 78(4):536-577.

Hägerstrand, T, 1970, What about people in regional science? Papers of the Regional Science Association 24, 7-21.

Hjorth, L and Kim, H, 2005, Being there and being here: Gendered customising of mobile 3G practices through a case study in Seoul. Convergence 11, 49-55.

Kanazawa S and Savage J, 2009, An evolutionary perspective on social capital. Journal of Economic Psychology, 30:873-883.

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Lauterbach, D, Truong, H, Shah, T, and Adamic, L, 2009, Surfing a web of trust: Reputation and Reciprocity on CouchSurfing.com. Proceedings of IEEE Social Computing 2009, Vancouver, British Columbia, Canada.

References Molz, JG, 2007, Cosmopolitans on the Couch: Mobile Hospitality and the Internet. In Mobilizing

Hospitality: The Ethics of Social Relations in a Mobile World, J.G. Molz and S. Gibson Eds. Ashgate, Aldershot.

Nyland, R and Near, C, 2007, Jesus is my friend: Religiosity as a mediating factor in Internet social networking use. AEJMC Midwinter Conference, Reno, NV.

Portes A and Landolt P, 2000, Social Capital: Promise and Pitfalls of Its Role in Development. Journal of Latin American Studies, 32(2):529-547.

Pultar, E and Raubal, M, 2009, A Case for Space: Physical and Virtual Location Requirements in the CouchSurfing Social Network. In International Workshop on Location Based Social Networks (LBSN'09) at 17th SIGSPATIAL ACM GIS 2009, eds. X. Zhou and X. Xie: November 3, 2009, Seattle, Washington, USA, 88-91, 2009.

Raubal, M, Winter, S., Teßmann, S, and Gaisbauer, C, 2007, Time geography for ad-hoc shared-ride trip planning in mobile geosensor networks. ISPRS Journal of Photogrammetry and Remote Sensing, 62, 366-381.

Thanks to the University of California Transportation Center (UCTC, www.uctc.net), the Jack and Laura Dangermond Fellowship, and the UCSB Dissertation Fellowship for funding this research.