TECHNOLOGY

22 | NewScientist | 16 March 2013

WE ARE already aware that our every move online is tracked, aggregated and analysed. But you couldn’t have known how much Facebook can learn about you from the smallest of social interactions – a ‘like’.

Researchers from the University of Cambridge designed a simple machine-learning system to predict Facebook users’ personal information and traits based solely on which pages they had liked.

“We were completely surprised by the accuracy of the predictions,” says Michal Kosinski, lead author on the paper (PNAS, DOI: 10.1073/pnas.1218772110).

Kosinski and colleagues built the system by scanning likes for a sample of 58,000 volunteers, and matching them up with other profile details such as age, gender and relationship status. He also matched up those likes with the results of personality and intelligence tests the volunteers had taken. The team then used their model to make predictions about other volunteers, based solely on their likes.

The system can distinguish between the profiles of black and white Facebook users, getting it right 95 per cent of the time. It was also 90 per cent accurate in separating

males and females, gay and straight men, and Democrats and Republicans. It can even predict whether a person takes drugs or has divorced parents, say, although with lower accuracy.

Personality traits like openness and intelligence were also estimated based on likes, and were as accurate in some areas as a standard personality test designed for the task.

Mixing what a user likes with myriad other data from their real-life activities could improve these predictions even more. Voting records, utility bills and

marriage records are already being brought into Facebook’s information fold, where they are easier to analyse. Facebook recently partnered with offline data giants Epsilon, Acxiom and Datalogix, which all collate this kind of information. This move will allow even deeper insights into the behaviour of the web populace.

Sarah Downey, a lawyer and analyst with privacy technology company Abine, foresees insurers using the information held by Facebook to help

them identify risky customers and perhaps tag them with higher premiums. But there are potential benefits for users too. Kosinski suggests that Facebook could end up as an online locker for your personal information, unleashing your profile at your command to personalise things like smart cars or to help you with career planning.

Downey says the research is the first solid example of the kinds of insights that can be made through Facebook. “This study is a great example of how the little things you do online show so much about you,” she says. “You might not remember liking things, but Facebook remembers and it all adds up.”

Making personality predictions this way is interesting because likes are visible to the public by default on new Facebook profiles, she says.

A Facebook spokesperson said this kind of insight into personal preferences has been around for years, although did not address the fact that tapping into this information is now easier than ever using its new Graph Search facility. “With Graph Search it’s not just whether you get a job, but whether you get a date,” says Downey. Hal Hodson n

You know me so wellFacebook can suss out your sex, race and personality, based on ‘likes’

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“Facebook could be an online locker for your personal detail, releasing your profile on command”

InsIghT Online privacy

NOT feeling your front crawl? Breaststroke a little off-kilter? Not to worry, a robotic swimming buddy can help you out.

Swimoid is a robot that glides along the pool floor underneath you as you swim, monitoring your form and providing real-time feedback on a 50-centimetre LCD screen.

Two cameras, one built into the front and one at the back of the robot, capture images of your stroke from below. A poolside coach can view these images on the screen and draw instructional diagrams over them for the swimmer to see as they swim – much like a football pundit does on television.

Yu Ukai from the University of Tokyo, Japan, says he built the system after experiencing the difficulties of teaching swimming from the side of the pool when he worked as an elementary school swimming instructor.

The robot was presented last week at the Augmented Human International Conference in Stuttgart, Germany.

Ukai says Swimoid could also be used to entertain young swimmers as they perform laps, and he has even developed a game on the robot to help introduce new swimmers to water. He also plans to remodel Swimoid as a scuba-diving buddy, adapting the robot to operate in open water. Hal Hodson n

Robo swim buddy snaps your stroke from below

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–Facebook never forgets…–

130316_N_TechLast.indd 24 11/3/13 18:07:58