You report that Lior Shamir of Lawrence Technological University in Michigan is looking for quantifiable ways of distinguishing the work of different painters (“Painting by Numbers,” July 30, 2011). In particular, he has programmed a computer to compare Salvador Dalí, Giorgio di Chirico, Max Ernst, Vasily Kandinsky, Claude Monet, Jackson Pollock, Pierre-August Renoir, Mark Rothko, and Vincent van Gogh. His claim is that computers may have just as good an eye for style as humans do. Surprisingly, you report, Shamir’s computer shows dramatically higher similarities between van Gogh and Pollock than between van Gogh and Monet or Renoir, for instance. And yet he maintains that the similarity between van Gogh’s brush strokes and Pollock’s dribbles requires further study on account of the computer’s subtle discoveries, including the similarities in the ways the two artists’ employed lines and edges. I wonder about such things in Pollock’s work, though. If the objective is to improve the ability to distinguish between different hands, as you argue, then Shamir had better return to his computer as soon as possible. Painting and dribbling ought to be told apart in a jiffy.