What we have here is a paper examining the use of twitter and individual smart phones in the computer science context, with each smartphone acting as a sensor. This could either be a sensor such as the GPS or microphone, recording automatically, or one involving human interaction, such as one asking the user to take a look at the weather and answer a given question.
In the context of our research using twitter for education, this is evidence of the power of the ‘wisdom of the crowd’ phenomena. For weather reporting, there was a 79% accuracy rate between crowd sourced weather reporting and that of weather.com. The other relevant figure it reports is that 1/6th of people are willing to take part in such activities with no apparent incentive. In other words, social learning projects itself.