Path lengths, alter networks, and small worlds

Through individual, group, and class engagement, the following two in-class activities demonstrate basic network concepts of path lengths, alter networks, and small worlds. They also provide the foundations for more complex concepts and measures. The activities are meant for non-computational/non-statistical introductory courses on social networks or for network modules in more general courses (social science, humanities), and for either high school or college undergraduate students. The first activity, Paths and Alter Networks, involves asking an initial person (ego) to name a known person (alter) who might personally know a third person (target) unknown by the initial person, and continues through additional alters, until the target is identified (or not). Over time, it reveals extended alter network paths that are otherwise unknown to ego, provides an example of network data collection, illustrates the small world process, and provides opportunities to generate real-time network data and discuss foundational network concepts. The second activity, Actor Small Worlds, performed within small groups, integrates the small world concept, especially in a very dense actor network, the Oracle of Bacon using IMDb data, and sociograms. It engages individuals by using and discussing their favorite actors and actresses, interacting with an Oracle of Bacon Pilot, and with a Drawer of Sociograms, iteratively developing a sociogram laying out the paths among actors based on common movies. Students interact to better understand central network concepts such as direct and indirect paths, small worlds, and dual-mode/affiliation matrices. This article briefly discusses goals, setup, procedures, lessons, and reflections for each activity.