How does a computer see meaningful trends?

Steven - Pattern recognition and data mining to reveal trends in data is a big part of computer science today. So we're learning more and more about that.Chris - The guys who did the work on Twitter and Facebook, they were using 2 billion tweets or something to work out what kind of mood people are in and what time of the day. So you're just telling the computer to look for certain words and certain words mean a good mood, certain words indicate on average a bad mood and you can extrapolate from that. The computer isn't actually reading. It's basically looking for trends which you tell it to look for.