Location is just one piece of information that can be generated by most smart phones, but is the most relevant for a marketer eager to deliver precise and context-specific messages to a consumer on the move. It is also a highly useful data point for a social scientist trying to measure the flow of human migration and socioeconomic progress, as in the case of Nathan Eagle’s research in the slums of Kibera, Nairobi, Kenya.

Between June 2008 and June 2009, Eagle and his co-researcher evaluated the calls recorded by mobile phones across Kenya (with all callers’ identification replaced with unique hashed IDs) to focus on calls originating or ending in Kibera. Their research tracked between 53,000 and 74,000 calls a month and a total of 18,000 individual callers during the year.

What did this data reveal about individual mobile phone users? “With each call, we can infer a number of individual characters such as

• spatial data (by the location of the cell tower that transmitted the call),
• economic data (the average length of each call, the amount of pre-paid minutes an individual has put on their phone, the type of phone),
• an individual’s regional or tribal affiliation, and
• a radius of migration for groups of individuals (by the distance between locations of cell towers calls have been made from).”

A first indication from this research is that Kenyans only live in the Kibera slum for a mean of 1.559 months. This high rate of movement and population turnover “supports the theory that slums act as a filter as opposed to a sink where there is a large amount of flux within the slum population.”

Amy Wesolowski, Nathan Eagle, Parameterizing the Dynamics of Slums

Eagle’s work in Kenya is an extension of a research project originally conducted at MIT, where 100 students were provided with mobile phones for 265 days. The mobile phones were equipped with custom survey software that recorded data and prompted the students with questions when certain conditions were met.

How much data?

“From the studies, we gathered 370 megabytes of raw data, including short recordings from 667 calls, 56,000 movements, 10,000 activations of the phone, 560,000 interaction events with our applications, 29,000 records of nearby devices, and 5,000 instant messages.”

Thankfully, from a privacy advocate’s point of view, the researchers also had to struggle with (a limited number of) weak points in their data sets – instances when the participants didn’t bring their phone with them, consciously turned the phone off, or simply ignored it. I would like to think that some of this reflected a conscious effort to mediate information collection, but it was probably just fatigue or forgetfulness.

There was one significant distinction between the two projects: the active involvement and acknowledgement of the participants. In Cambridge, the participating students were walked through the information collection process, provided with details about the information that would be collected, and required to complete a consent form(.pdf).

M. Raento, A. Oulasvirta, N. Eagle, “Smartphones: An Emerging Tool for Social Scientists“, Sociological Methods Research 37:3, 426-454.

This is an important point when it comes to the collection of location data, especially when it is associated with other personal information: individuals want to know what is happening with their information, and would like some element of control over its use.

A recent and exhaustive examination of the 89 then-available location-sharing services (really, who can keep track?) by researchers from Carnegie Mellon University noted that “the willingness to share one’s location and the level of detail shared depends highly on who is requesting this information (or knowing who is requesting this information), and the social context of the request.”

Supplemental interviews confirmed that potential users had particular scenarios in mind when evaluating the benefits and risks of these services: scenarios that would best be addressed with more detailed privacy controls, rules and conditions (explained in detail in the paper):

• Blacklists
• Friends Only rules
• Granularity of controls
• Group-based rules
• Invisible status
• Location-based rules
• Network permissions
• Per request permission
• Time-based rules
• Time-expiring approval, or
• No restrictions

Janice Y. Tsai, Patrick Gage Kelley, Lorrie Faith Cranor, Norman Sadeh, Location-Sharing Technologies: Privacy Risks and Controls

Obviously, there are significant gaps in how personal privacy is protected when information is collected and analyzed in a large scale research project, a smaller experiment and within the context of online commercial services.

“girl chewing gum” is a similar work – a continuous film of a city street, at a point during 1976 in a rather plain part of East London.

This time, however, a soundtrack is overlaid to create the illusion that the pedestrians within the frame are being given stage instructions by the ostensible director, John Smith.

This pretense begins to fall apart as the film progresses, but it serves to remind us that any film is subject to interpretation and misinterpretation. The eye of the beholder is naturally informed by personal experience, rough class distinctions reinforced by clothing and gait, social and economic bias, among many other factors.

Notably, the director’s ability to anticipate a pedestrian’s behavior is limited by his range of vision, and his false stage directions are influenced by his ability to rewind and review.

In any case, his film reflects bare moments in the life of each pedestrian, ignorant of their thoughts, the impulse that led to their walking down Stamford Road,or their eventual destination.

Thanks to Joe Moran for pointing out the film’s appearance online.

Commentary from Library of Congress archivists, who restored the film nearly forty years ago, noted that some of the streetscape was staged:

“… a careful tracking of automobile traffic shows that almost all of the autos seen circle around the camera/cable car many times (one ten times). This traffic was apparently staged by the producer to give Market Street the appearance of a prosperous modern boulevard with many automobiles …”

Nevertheless, the behaviour of the many pedestrians offers some insight into early reaction to the presence of a camera in public. In the opening minutes of the film, the camera does not seem to affect behaviour on the street. Some gentlemen preen and pose as they spot the camera, but most go about their business. There are some expressions of surprise, as even a camera is a novelty for the time. Some seem to be upset that the streetcar, despite the camera, will not stop to pick them up.

The longer the camera travels down the street, though, the more blatant the behaviour change. I’ve clipped a few stills from the film to illustrate these points:

• Some, expecting the streetcar to stop for their signal, were perplexed
• One man noticed the camera, then tilted his hat and sped up to avoid having his face captured on film
• Several car loads of men appear and reappear throughout the film
• One man notices the camera, stops to have his image recorded, then runs farther down the street so he can stand directly in the path of the streetcar for several seconds.
• Children, of course, dart in an out of the frame. At the very end of the film, a handful of kids seize control of the scene.

Consider the very different results when a similar film was made in Vancouver, in 1907: the filmmaker spoke to the local newspapers about his plans and actively encouraged citizens to step into the frame. The result?

“… the Vancouver Province reported that “many prominent citizens were suddenly stricken with kinetoscopitis yesterday” and reassured readers that “kinetoscopitis is not nearly as serious in its effects as spinal meningitis.” The article observed that “the way that prominent citizens suddenly discovered that they had business on the other side of the street and strolled across sort of unconcerned like, when they saw the kinetoscope coming was very amusing to those on the front of the car.”

In contrast, public surveillance is very much expected today. Just look at a Google Maps mashup, created yesterday, of the locations from which members of the public filmed the tasing of a Phillies baseball fan chased across the field at Citizens Bank Park – and then posted that footage online.

*see more on the debate about the film’s date at the SFGate blog. Recent research suggests this film was shot just days before the 1906 earthquake – which destroyed much of Market Street.

**did you see the guy on a horse?