Algebra is now often called snapshot algebra or algebra of seeing because of this dependence on time. If any action or event were possible between steps in algebraic analysis, then, in theory, one would have to start over as if one had no knowledge of the new state at all. For these reasons the idea of statistics and also knowledge and knowledge management are sometimes questioned, for instance, in the book "Lies, Damn Lies, and Statistics". A major issue is the comparing of numbers gathered in the past, and now, after some key conditions change.