User studies are necessary not only for planning and designing information systems but also for their efficient and effective operation. User studies, to ascertain the patterns of information use by researchers and scientists, are considered important in planning and designing of information system and services. The effectiveness of a library system depends upon the extent to which the system characteristics correspond with the users and on how much the potential user is willing and able to make use of it. The application of results of user studies to the design of new information services and the improvement of existing services is of utmost importance. The decision makers should be aware of the information need of the users for making more informed decision about library services. User study help in making it clear how to perform relevant duties and serving the best possible way to satisfy their ultimate users attaining their satisfaction level and by diminishing the unsatisfactory elements of library. This book provides an overview of various concepts related to user studies. It covers wide range of topics related to user studies such as information needs of the users, various methods of assessing information needs, various statistical methods useful for user study, report writing etc. The present work is divided into 13 chapters: Chapter 1: An Introduction to User Studies; Chapter 2: Implications of User Study; Chapter 3: Understanding the Concept of Information and Information Need; Chapter 4: Different Categories of User and Their Information Needs; Chapter 5: Concept and Methods of Information Seeking Behavior; Chapter 6: Methods of Conducting User Studies; Chapter 7: Steps in Conducting User Studies; Chapter 8: Statistical Methods for Data Analysis; Chapter 9: Interpretation, Analysis and Presentation of Data; Chapter 10: Writing Research Reports; Chapter 11: User Studies and User Education; Chapter 12: Information Literacy Programme; Chapter 13: An Account of Some Important User Studies and their Findings in addition to Bibliography and Glossary. The main objective of writing this book is to provide sufficient knowledge about the various concepts related to user studies in detail, systematically and comprehensively. Special care has been taken to describe the various concepts related to user studies in a very simple and easy language. A detailed glossary is given at the end to understand the terms without any difficulty. A numbers of case studies and sample questionnaires are also given for better understanding of the concept of user studies. User Studies: A Tool for Measuring Library Performance intends to serve as a handbook for the students, teachers, researchers and practitioners in Library and Information Science. This book not only deals with theoretical aspects of the concept of user studies but also covers the practical aspects. It is specially designed to meet the requirement of students of M.L.I.Sc., M.Phil., Ph.D. and for those doing research work in the area of user studies of various universities and institutions.