SocialCircuits : The Art of Using Mobile Phones for Modeling Personal Interactions

1. SocialCircuits:The Art of Using Mobile Phones for Modeling Personal Interactions Wayne Stilwell CS 595 September 29, 2011

2. What is it? • Platform that uses mobile phones and surveys to capture relationships and influences in a dense community • Mobile phones track interaction with others • Surveys track changes in habits, opinions, and health

3. Experiment at a glance • Deployed on a “physically and socially distant” college dorm in the 2009-2010 school year • Over 65 of 90 students participated • Some declined due to privacy concerns • 65% of residents said most of their friends/contacts lived in the dorm • Data captured: • 3 million co-location samples • 60,000 phone calls • 20,000 text messages

4. Devices used • Based on Windows Mobile 6 • Students transferred existing voice plans • Tested on Verizon, AT&T, Sprint, and T-Mobile • Works on 6 different smart-phones • Source code available at: http://mob.media.mit.edu

5. System capabilities • Detect nearby Bluetooth devices • Detect WiFi access points • Log phone calls and text messages • Background scan manager • Ensures Bluetooth and WiFi are activated • On-device survey launcher • Launches daily surveys when phone is turned on

6. System capabilities • On-device user feedback engine • Students could respond to other’s responses • Over-the-air application updater • Custom Music Player • Students could play, share, rate, and search through a library of 1500 tracks • Flexible integration with web-based survey • MySQL tables generated for each user for data analysis

7. Study: Political opinions • Goal is to see how our opinions diffuse across our social networks • Surveyed students 3 times (each month before the election) • Asked their interest in politics & party preference • Based on these results, and who a student interacted with, they could predict if that person is likely to accept or reject new opinions

8. Tips for future attempts • Mobile phone sensors • Using GPS and Bluetooth to track location and proximity are useful, but both must be enabled • Accelerometers are less accurate if the phone does not remain at a fixed spot on the body

9. Tips for future attempts • Platform Openness, Cross-Carrier Support • Only a jail-broken iPhone could run this platform at the time • For a large-scale experiment, just use a single app (instead of manually installing software on hundreds of phones)

10. Tips for future attempts • Community Selection • Density is more important than volume • Want to track as many reasons as you can why someone’s behaviors changed

11. Tips for future attempts • Community Preparation • Some were concerned about privacy • Ironically their concerns “diffused” to others • Personal identifiers in data were hashed, disguised, and removed • Some were uncomfortable doing the surveys. So they were not mandatory. • Students were also paid $1/day each time they filled out a survey.

12. Tips for future attempts • Long-Term Reliability • Get help on the ground • Encourage participants to report problems • Students offered $10 to be first to report a bug • Use minimal amount of handsets • More handsets = more costly bugs • Avoid on-device flash memory • They wrote every 5 minutes for 3 months, then the disk failed • Pay subjects incrementally