Most libraries involved to any extent with total quality management (TQM) realize that successfully gathering information from their customers is the key to improving services. To do this libraries must employ a variety of methodologies, both quantitative and qualitative research. Quantitative primary data is usually collected in libraries by survey or by observation. Types of surveys include on-the-spot questionnaires, mail surveys, phone surveys, or in-person interviews, and the advantages and disadvantages of each are listed. Survey researchers must consider: (1) what they want to know; (2) whom they need to interview; (3) how they are going to select people to interview; (4) how many people they need to interview; (5) what questions will be asked; (6) how to administer the questionnaire; (7) how to analyze the data; and (8) how to glean meaning from the results. Qualitative research often involves focus groups, which can be used to determine how well existing services meet clients' needs; help design quantitative studies; supplement data collected through a user survey; provide insight into non-use; plan for a new facility; and solicit input on electronic resources. To be successful, focus group discussions must have established research goals; an identifiable target audience; an objective, enthusiastic, and knowledgeable moderator; a carefully planned discussion; a record of session; and a comfortable facility. (Contains 27 references.) (Author/BEW)