Encyclopedia of Statistics is a prime source of information about theory, methods, and statistical applications for researchers. This valuable work has established itself as the most prominent reference for those in the fields of statistics, probability theory, biostatistics, quality control, and economics and also for those who are working in relation to the applications of statistical methods in sociology, engineering, computer science and communication, biomedicine, and psychology. The first step in preparing the Encyclopedia of Statistics was taken in 1997 with the formation of the "Council for the Encyclopedia of Statistics ". The council formed the basis for the compiling of the Encyclopaedia of Statistics, the 13-volume (9 major volumes, 1 supplementary volume, and 3 updated volumes) Encyclopedia of Statistical Sciences, whose editor in chief is Samuel Katz. Due to the scope of work and time-consuming completion of each volume of Persian, the Council of Encyclopedia of Statistics decided to print each volume of Persian in several parts to expedite the use of parts of this Encyclopedia for those interested in statistics in the country, then publishes the complete volume. Therefore, the first part of the first volume was published in July 2001 and the second part in September 2002, and in April 2004, the second edition of the first and second parts and the third part in the form of the first volume, which includes 292 articles and 742 pages, Printed and published.