Research libraries
A research library contains an in-depth collection of material on one or more subjects.[33] A research library supports scholarly research and will generally include primary as well as secondary sources; it will maintain permanent collections and attempt to provide access to all necessary material. A research library is most often an academic or national library, but a large special library may have a research library within its special field and a very few of the largest public libraries also serve as research libraries. A large university library may be considered a research library; and in North America they may belong to the Association of Research Libraries.[34] A research library can be either a reference library, which does not lend its holdings, or a lending library, which does lend all or some of its holdings. Some extremely large or traditional research libraries are entirely reference in this sense, lending none of their material; most academic research libraries, at least in the U.S., now lend books, but not periodicals or other material. Primary sources are original materials.[1] Information for which the writer has no personal knowledge is not primary, although it may be used by historians in the absence of a primary source. In the study of history as an academic discipline, a primary source (also called original source or evidence) is an artifact, a document, a recording, or other source of information that was created at the time under study. It serves as an original source of information about the topic. Similar definitions are used in library science, and other areas of scholarship. In journalism, a primary source can be a person with direct knowledge of a situation, or a document created by such a person. Primary sources are distinguished from secondary sources, which cite, comment on, or build upon primary sources, though the distinction is not a sharp one. Generally, accounts written after the fact with the benefit of hindsight are secondary.[2] A secondary source may also be a primary source depending on how it is used.[3] "Primary" and "secondary" are relative terms, with sources judged primary or secondary according to specific historical contexts and what is being studied.[4]:118–246[5] In scholarship, a secondary source[1][2] is a document or recording that relates or discusses information originally presented elsewhere. A secondary source contrasts with a primary source, which is an original source of the information being discussed; a primary source can be a person with direct knowledge of a situation, or a document created by such a person. Secondary sources involve generalization, analysis, synthesis, interpretation, or evaluation of the original information. Primary and secondary are relative terms, and some sources may be classified as primary or secondary, depending on how it is used.[3][4][5][6] An even higher level, the tertiary source, such as an encyclopedia or dictionary, resembles a secondary source in that it contains analysis, but attempts to provide a broad introductory overview of a topic.[7]