12 3 Decision makers and socializers , social networks 4 and the role of individuals as participants 5

8 Abstract Models explaining and predicting human travel behavior have gone through 9 many changes in the past few decades. As researchers attempt to explain more and predict 10 with more accuracy, the inclusion of social interactions in modeling and simulation is 11 being recognized as a necessity. Among these efforts, researchers have focused on issues 12 such as the composition of social networks, and the constraints and influences that others 13 have on spatial decisions. An important aspect that has been understudied however is the 14 variability or heterogeneity of individuals both as social network members and as partic15 ipants in these social networks. Understanding the role individuals play in decision-making 16 in different social networks can further define our models to include more accurate rep17 resentations of human behavior. This research explores the differences between social 18 network composition, and the decision roles members play within different social networks 19 specifically when deciding where to participate in activities. A survey was conducted in 20 Santa Barbara, California on social network involvement, network attributes and decision21 making roles within each network. Two separate latent class cluster analysis models were 22 developed to classify social network involvement and roles. Results show that there are 23 clearly different types of social involvement and roles within networks. Further data 24 collection and analysis will be used to better understand how these decision-making roles 25 manifest themselves in activity decision-making.