the so-called principle of least effort is sometime referred to as the law of least effort or Zipt's law. It originnally appeared in book by George Zipf (1902-1950) of Harvard University, whose area of expertise was philology what today we would call linguistics. The book, published in 1949, was entitled Human behavior and the princi-ple of least effort : An introduction to human ecology. Zipf initially developed the PLE through statistical analysis of word occurrence in developments, and by analyzing other artifacts of human activity, such as the census and other government rrcord. Zipf intendef to develop a broad explanation for human activity.