This synthesis of studies came about when one of the authors, who was searching for a unified theory of writing center tutoring, discovered that it would require analyzing existing studies to mine them for theories. The authors note that writing centers began appearing over a 20-year period beginning in the late 20th century. Among the topics addressed are: personal characteristics of participants, external influences, communication and emotion, roles, temperament, and outcome. Each chapter except the conclusion ends with a summary. Authors are Babcock (English, U. of Texas of the Permian Basin), Manning (writing center director and coordinator of developmental English, Frank and Sue Mayborn School of Journalism), and Rogers (U. of Texas and project research assistant). Annotation ©2012 Book News, Inc., Portland, OR (booknews.com)