If you are looking for Primary Sources in history, please see our FAQ item for that.
A rule of thumb used on this campus for evaluating whether or not a scientific article is a primary source is that it has a "Materials and Methods" section. If it has such a section, it is primary. If you are assigned to just get a few primary articles, that will probably work for you. Just search for articles and examine them for that section. However, if you need to do more serious research, read on:
In the sciences, a primary literature is the original publication of a scientist's new data, results, and theories. We have no direct mechanisms in our search products that filter for these, so it is a matter of judgment as to whether or not a source is primary. Journal articles are the main format in which primary literature is found, but there are many articles published in scholarly / academic journals which are not primary literature, particularly review articles, which do not report new findings but review what is already known. Also, there are some websites which constitute primary literature (here,here and here, for example) which are full of credible primary data and are not likely to be published in journal article or even book form. Note that being "primary" is in itself no indicator of the quality of the item (see here and here ); for that we use peer reviewed, and to a lessor extent, the designation academic / scholarly.
The rule of thumb listed above (does it have a "Materials and Methods" section?) will work for most of the articles you will come across. There are some exceptions to that rule, however. The best thing is to use your judgment.
Secondary literature includes review articles (which include reviews of the literature) textbooks, and most scholarly or academic books (that repeat information that is already published). The vast majority of popular periodical publications (magazines, trade journals, newspapers) are usually considered tertiary literature, in that they are repeating information that has already been published and they are usually written for a non-technical audience .
Note that the vast majority of empirical articles (a term used in Education and Social Sciences) are probably primary literature, but not all empirical articles are primary.
These examples and descriptions of publication types will give you an idea of how to use various works and why you would want to write a particular kind of paper.
- Scholarly article aka empirical article
- Review article
- Conference paper
Scholarly (aka empirical) article -- example
Empirical studies use data derived from observation or experiment. Original research papers (also called primary research articles) that describe empirical studies and their results are published in academic journals. Articles that report empirical research contain different sections which relate to the steps of the scientific method.
Abstract- The abstract provides a very brief summary of the research.
Introduction- The introduction sets the research in a context, which provides a review of related research and develops the hypotheses for the research.
Method- The method section describes how the research was conducted.
Results- The results section describes the outcomes of the study.
Discussion- The discussion section contains the interpretations and implications of the study.
References- A references section lists the articles, books, and other material cited in the report.
Review article -- example
A review article summarizes a particular field of study and places the recent research in context. It provides an overview and is an excellent introduction to a subject area. The references used in a review article are helpful as they lead to more in-depth research.
Many databases have limits or filters to search for review articles. You can also search by keywords like review article, survey, overview, summary, etc.
Conference proceedings, abstracts and reports -- example
Conference proceedings, abstracts and reports are not usually peer-reviewed. A conference article is similar to a scholarly article insofar as it is academic. Conference articles are published much more quickly than scholarly articles. You can find conference papers in many of the same places as scholarly articles.