Donald Knuth's influence in computer science ranges from the invention of methods for translating and defining programming languages to the creation of the TeX and METAFONT systems for desktop publishing. His award-winning textbooks have become classics; his scientific papers are widely referenced and stand as milestones of development over a wide range of topics. The present volume, which is the fourth in a series of his collected works, is devoted to an important subfield of Computer Science that Knuth founded in the 1960s and still considers his main life's work. This field, to which he gave the name Analysis of Algorithms, deals with quantitative studies of computer techniques, leading to methods for understanding and predicting the efficiency of computer programs. More than 30 of the papers that helped to shape this field are reprinted and updated in the present collection, together with historical material that has not previously been published.