How do computers see the world?  Can they tell if we are happy?  Can they predict what we are going to have for dinner next Tuesday?  Can they recognize when we are sick?

Well, my iPhone can.  Sort of.

I was (finally) recovering from a nasty cold last week and I opened the Health app on my phone and noticed that the step-counter had fairly accurately captured my cold, from start to finish.  My normally active body had flatlined for over three weeks, except for one day where I thought I was getting better and went snowshoeing for 8 miles in the Mount Evans Wilderness.  Bad idea.

So why didn’t my phone send me a sympathy card?  Well, that’s the problem with data.  It’s just data.  It takes skillful, and contextual, interpretation to make sense of the data and to draw useful conclusions.  With the step data, a computer might notice a trend or anomaly, but it doesn’t understand that it was caused by working out more or being sick in bed.  That is the art of data science and knowledge discovery.  A graph is just a graph until someone interprets it.