Scientific journal


 * For a broader class of publications, which include scientific journals, see Academic journal

In academic publishing, a scientific journal is a periodical publication intended to further the progress of science, usually by reporting new research. Most journals are highly specialized, although some of the oldest journals such as Nature publish articles and scientific papers across a wide range of scientific fields. Scientific journals contain articles that have been peer-reviewed, in an attempt to ensure that articles meet the journal's standards of quality, and scientific validity. Although scientific journals are superficially similar to magazines, they are actually quite different. Issues of a scientific journal are rarely read casually, as one would read a magazine. The articles are written as part of the scientific method; they generally must supply enough details of an experiment, so that an independent researcher could potentially repeat the experiment to verify the results. Such journal articles are considered part of the permanent scientific record. The standards that a journal uses to determine publication can vary widely. Some journals, such as Nature, Science, PNAS or Physical Review Letters, will not publish an article unless they believe that it marks a fundamental breakthrough in its field, and hence will reject papers which contain good work that does not meet this criterion. In many fields, an informal hierarchy of scientific journals exists; the most prestigious journal in a field tends to be the most selective in terms of the articles it will select for publication. It is also common for journals to have a regional focus, specializing in publishing papers from a particular geographic region.

Articles tend to be highly technical, representing the latest theoretical research and experimental results in the field of science covered by the journal. They are often incomprehensible to anyone except for researchers in the field. Scientific journals are a crucial part of the scientific literature.

Types of articles
There are several types of journal articles; the exact terminology and definitions vary by field and specific journal, but often include:
 * Letters (not to be confused with letters to the editor) are short descriptions of important current research findings which are usually fast-tracked for immediate publication because they are considered urgent.
 * Articles are usually between five and twenty pages and are a complete descriptions of current original research finding, but there are considerable variations between scientific fields and journals: 80-page articles are not rare in mathematics or theoretical computer science.
 * Supplemental articles contain a large volume of tabular data that is the result of current research and may be dozens or hundreds of pages with mostly numerical data. Some journals now only publish this data electronically on the internet.
 * Review articles do not cover original research but rather synthesize the results of many different articles on a particular topic into a coherent narrative about the state of the art in that field. Examples of reviews include the 'Nature Reviews' series of journals and the 'Trends in' series, which invite experts to write on their specialisation and then have the article peer-reviewed before accepting the article for publication. Other journals, such as the Current Opinion series, are less rigorous in peer-reviewing each article and instead rely on the author to present an accurate and unbiased view.
 * Research notes are short descriptions of current research findings which are considered less urgent or important than Letters

The formats of journal articles vary, but almost always follow the following general scheme. They begin with an abstract, which is a one-to-four-paragraph summary of the paper. The introduction describes the background for the research including a discussion of similar research. The materials and methods or experimental section provides specific details of how the research was conducted. The results and discussion section describes the outcome and implications of the research, and the conclusion section places the research in context and describes avenues for further exploration.

In addition to the above, some scientific journals such as Science will include a news section where scientific developments (often involving political issues) are described. These articles are often written by science journalists and not by scientists. In addition some journals will include an editorial section and a section for letters to the editor. While these are articles published within a journal, they are not generally regarded as scientific journal articles because they have not been peer-reviewed.

Issues
It has been argued that peer-reviewed paper journals are in the process of being replaced by electronic publishing. There is usually a delay of several months after an article is written before it is published in a journal and this makes journals not an ideal format for disseminating the latest research. In some fields such as astronomy, the role of the journal at disseminating the latest research has largely been replaced by preprint databases such as arXiv.org. However, scientific journals still provide an important role in quality control, archiving papers, and establishing scientific credit. In general, the electronic materials uploaded to preprint databases are still intended for eventual publication in a peer-reviewed journal.

Another controversy is the cost of scientific journals. Many scientists and librarians have protested against the cost of journals, especially as they see these fees going to large for-profit publishing houses. Also the fact that copyright is assigned to the journal publisher, and not the authors, causes much discussion.

There is an article titled "Online or Invisible?" (see below) which uses statistical arguments to claim that electronic publishing provides wider dissemination. A number of journals have, while retaining their peer-review process, established electronic versions or even moved entirely to electronic publication.