Quantitative methods, such as graphs, present information visually for the researcher. Graphs typically answer the question of "how often?" or "how many?" within library science research. For example, the use of library patron statistical data within graphs, such as how many patrons visit a library on a given day, helps the library determine operation hours.
Statistics is the collection and analysis of numerical data for research. Statistics offer a tool for librarians to predict trends within library science such as the growing use of electronic databases within academic libraries during a specific time period. Statistics also test hypotheses or problem statements within library research.
According to the Journal of the Medical Library Association, bibliometrics is "the measurement of interrelated aspects of writing, publication, and usage, including citation analysis." Using quantitative analysis and statistics, library science researchers use bibliometrics to determine the popularity or influence of a specific author or text. The research collected in a bibliometric study helps libraries determine if a specific text is worth purchasing.
Observation uses the senses, such as sight and hearing, to obtain information about a particular human behavior or object. The qualitative research method of observation provides the opportunity for raw, in-depth data collection within library science research. For example, by observing a library patron's frustration with a certain new technology, observation may conclude that the library needs to provide additional instruction for the patrons.
An interview gathers information from conversations and questions between a researcher and subject. This method of qualitative research often examines the "why?" and "how?" behind a problem or human behavior. Interviewing rural library directors regarding the specific issues a rural library may face during a difficult economy is one example of interview research.
Surveys are carefully constructed questions. The use of surveys differ, and responses range from opinions to factual information. For example, surveys used in library science may determine the opinions of library patrons regarding new library hours or how often a patron participates in library events.
Libraries may assemble focus groups for the purpose of obtaining opinions, feedback or beliefs about a particular product or idea. For example, a focus group may provide feedback about a possible new library reference service.