The major issues with Information Retrieval (IR) system are the huge collection of information available on the web and query keywords used by users often are short, confusing, and ambiguous. Users are often not wishing to see long list of results presented by the retrieval systems to find relevant information. It has been observed that users typically view only top few results comes in first few pages. This book is intended to review the issues in recent developments in personalizing IR and to discuss the development of new techniques targeted to resolve the issues associated with IR by means of re-ranking search results and search query reformulations. The book investigates the issues in personalizing IR and focusing on user profile representation and exploitation. It is observed that the process of acquisition and representation of user profile could be improved for the effectiveness of document re-ranking and query reformulation in retrieval process. This book also discusses the various evaluation measures applicable to measure the performance of personalization approaches in IR. The contribution of the book is of four folds. The detailed investigations are given inside.