It is valid. The paper is intended to explain how the data can be calibrated.
While Robinson says his multitude of mobile phones can provide large amounts of data, individual areas still need to be fine-tuned using existing weather stations before the incoming information can be usable for weather prediction.
““The challenge is whether we can take this technique and use it in places where we don’t already have reliable weather information to retune the model,” said Robinson. "That's something we're still working on."”
I don't know if she intended it for you or not but this does offer incite in how you can avoid the data being skewed by the phone being in your pocket or with you in an air conditioned room.
I was asking for the general point of this thread, not specifically about your response to desh. But, I quoted your response, so sorry for the confusion.
Being accurate to 1.5 degrees is pretty good for a weather app. You did not post the article but you joined in on the misreading/misrepresentation of the application by stating...
given the global warming fear mongers are talking about changes of 0.12 degrees per decade, I would say they have a very very long way to go before using this type of data.