Logo Netzwerk Stadt Landschaft NSL
Logo ETH Zürich


An iterative survey of social networks

               An iterative survey of social networks

Transport planning has exhibited increasing interest in the methods of social network analysis in recent years. The primary goal of previous investigations was to analyse the spatial distribution of an individual’s network of contacts. Findings showed that in most cases, the network components remained isolated from one another. It is the aim of a new project to collect data on connected personal networks and obtain a view on the comprehensive network structure.

Explanations for leisure travel are challenging the field of transport planning. Recent empirical work has confirmed leisure activities as primarily a joint undertaking, rather than an individual action. Accordingly, leisure travel can be characterised as “social travel.” In using the methods of social network analysis, transport planning aims for new modelling approaches regarding leisure travel, by taking into account the influence of a singular actor’s social environment.

In a joint survey project, the Institute for Transport Planning and Systems IVT (ETH Zurich) and the Institut für Land- und Seeverkehr ILS (TU Berlin) are collecting information on personal networks. The survey focuses specifically on the degree of homophily, that is, the similarity between the respondents and their contacts, e.g. in terms of socio-demographics, the spatial distribution of the contact network, and the places and contexts in which persons first came into contact. This result is combined with information on the communication modes and frequencies used to maintain the relationship between the respondent and his or her contacts. In order to not only collect information on isolated network components, but to get behind them, a snowball approach (or ascending sampling strategy) is employed to survey the distribution of connected egocentric structures. Starting with a base of 60 randomly selected respondents in the Canton of Zurich, the project aims to expand and recruit at least 500 respondents within two iterations. Since each respondent reports an average of 15 social contacts in the survey and provides additional information on these contacts, a database of around 7500 persons will emerge.

Kay W. Axhausen
Matthias Kowald

Kowald, Matthias; Frei, Andreas; Hackney, Jeremy K.; Illenberger, Johannes; Axhausen, Kay W. (2009): Collecting data on Leisure Travel: The Link between Leisure Acquaintances and Social Interactions. Paper presented at «Applications of Social Network Analysis» (ASNA). Zürich, September 2009. Mehr