The computer is to the 20th century as the printing press was to the 15th; it has changed the way we think and act--even though many of the changes are subtle and the impact is more cumulative than dramatic. Nevertheless, the author says, ""The tool had become nothing less than a vehicle for inducing a change in behavior."" McCorduck explores examples supporting this idea in areas ranging from sport to art to public policy; but her efforts--especially in the book's first third--are hampered by some self-inflicted wounds of an excessively chatty style and disconcerting presentation. One intriguing chapter shows the teaching of computer skills to children in Senegal, an African nation where adult literacy is shockingly low and where reliable sources of electricity are rare. The author also looks at computers speeding up medical analyses but creating moral dilemmas: how much should a computer be used to supplant the tradition of consulting fellow doctors, and how much extra cost is justified by the miracles of artificial intelligence? On the lighter side, she takes us to an adult computer camp where ""students"" come to conquer their computer phobias. But interesting examples are often sublimated to flashbacks into her childhood, constant references to what she has said in previous chapters (and what she will say in future ones), a heavy dose of rhetorical questions, and an assortment of parenthetical digressions that slow the book's pace. ""I could summarize the history of artificial intelligence as an adventure story. . .,"" she writes in an early chapter. The reader would have been better served if she had.