Michael Gray believes personalized search can make the searcher miss out on what an algorithm could never find: the human touch of serendipity. He gives an example of a quirky New York Times story about a New York City debutante who was the real-life model for a character on "Gossip Girl" -- and is also trying to have a monument built for her ancestor James Madison. "This was a story chosen to be featured in the New York Times by a human editor, not by an algorithm," he writes. "This kind of random discovery is what the editors are really good at and where computers fail."