the collection planning for new collections or collection areas institutional mission cooperative decision-making with other libraries or within library consortia According to the IFLA there are four primary reasons for a written collection development policy: selection, planning, public relations, and the wider context. A written selection guidelines provide staff with the tools to access and evaluate potential additional collection materials as well as basis for denying the acceptance of materials. Beyond the addition of new materials this section can also define the parameters for weeding materials, storage standards, and preservation of unstable collection objects. Secondly, planning aids in making decisions for future improvement in library infrastructure and proper distribution of funds for the institution. Thirdly, in the current environment of limited funding and competition between departments and agencies, a written collection policy aids in the library's public relations. This document can be a tool to help potential donors or funders assess the needs of the library, including assets and services. Lastly, in terms of the wider context, the document can aid in collaboration with other institutions in an effort to fulfill the needs of their patrons and community. Each institution will have a better understanding of the plans for each and how they can assist each other in achieving these goals. Weeding Weeding also known as de-selection of information materials is a and practice of discarding or transferring to storage, excess copies and rarely-used books and materials. It also involve removal of library material from the collections based on some determined conditions. Historically, both patrons and other librarians criticize weeding books. Some believe libraries should keep all materials in circulation no matter the condition or need for room in the facility for newer material. The controversial nature of collection weeding necessitates the educating of library staff. It provides them with "the tools they need to counter common perceptions or misperceptions regarding weeding", especially those encountered from faculty in an academic library. Educating the staff with workshops and presentations on collection quality, maintenance and the importance and positive benefits of weeding the collection are important components for a library to consider. Collection evaluation methods Some library evaluation methods include the checklists method, circulation and interlibrary loan statistics, citation analysis, network usage analysis, vendor-supplied statistics and faculty opinion. Therefore, without an ongoing weeding program, a collection can quickly age and become difficult to use. However, in order to have a continuous weeding