The cycle of scientific literature is an idealized picture of how scientific literature gets produced. This model shows a process that is continuous and doesn't have exact endpoints. Scientific literature presents the results of scientific work--including both library and laboratory research. Before research begins, the researcher (i.e., the scientist) identifies the topic of interest. Inspiration for a topic can come from many sources--a journal article, a news clipping, or a science documentary on TV. The researcher needs to be intrigued by a topic, then ask questions about what he or she wants to investigate further.
The growth of scientific knowledge depends crucially on the research step. Research includes library research, through which the scientist refines his or her hypotheses, and experimental research in the laboratory or field, through which the scientist tests his or her hypotheses. Preliminary research activities would include finding out what is already known about a topic, finding out what is not known, and using this information to refine the hypothesis. Then original research begins--designing experiments to test scientific hypotheses.
One of the most important stages in the cycle of scientific literature is the writing and dissemination of journal articles. Articles in scientific journals present new results from scientific research in an authoritative context and preserve the results of past research. The most respected journals include articles that are peer reviewed by other scientists who can best evaluate the work.
Conference proceedings and journal articles that report original research make up the primary literature of science. This term refers to the importance of these types of works, and also to the fact that they record the first results of original research.
The cycle continues as the results of research presented first in journal articles are later refined and summarized for a wider audience (students, general readers) in edited volumes (such as annual reviews) and textbooks. These types of scientific literature present information that over time, through research, dissemination, and examination by other scientists, comes to be considered most significant and authoritative. Such sources are enormously important in the teaching of science.
Edited volumes, books that describe the work of many scientists, and textbooks make up the category of scientific literature called secondary literature. Secondary scientific literature synthesizes and summarizes the theories and results of research. Many popular scientific magazines such as Natural History and Science News belong to the secondary literature category, not primary literature (despite the fact that they include articles), because the articles in them do not present results of original research, rather, these articles summarize and describe research activities.
Finally in the cycle of scientific literature, information is compiled into scientific reference sources, such as encyclopedias and handbooks. Reference sources offer overviews of scientific topics, data, facts, and definitions. Generally reference sources are viewed as giving authoritative scientific information, but among different reference works, information may vary. This is a reflection of the fact that reference sources distill scientific information based on original research, an activity that always questions how things work. Reference sources may be used in preparing for a new topic and a new research project, and in starting activities that will lead to the production of new scientific literature.
A note on the timeframe: the cycle of scientific literature represents a process that takes a lot of time. The time it takes to identify a research topic, complete library and laboratory research, and write up a journal article may take several years--much will depend on the individual scientist and the complexity of the research problem. As for the other part of the cycle, secondary literature and reference sources, the results of some scientific work may never find its way into a textbook or reference source. The cycle represents all the possible types of scientific literature produced in the course of scientific work, not the results of a single project.