It was Sir Isaac Newton who, as far back as in 1676, wrote in a letter to Robert Hooke: “If I have seen further than others, it is by standing upon the shoulders of giants.” The scholarly tradition of acknowledging the work of others continues to date in the form of citations, which are the foundation of the whole edifice of prestige in science in the form of Journal Citation Reports, Impact Factor, H-Index, and a slew of other bibliometrics. The acknowledgment is not so much of people as of sources, which are various and have their own features, forms, and credibility.
Features of Documentary Sources
Features of Documentary Sources
Research is incremental: a research paper draws upon data, conclusions, interpretations, opinions, observations and so on of others; adds to them a piece of original research conducted by the authors of the paper as their contribution to the growing body of knowledge; and in turn used by yet others as a source to serve their own research, earning a due acknowledgment from them. It is crucial to understand, however, that all sources are not equal but form a hierarchy, and it is important that researchers recognize that hierarchy early in their careers.
The sources include scholarly journals and books, reference books and manuals, trade journals, popular science magazines, newspapers, mass-market magazines, websites, podcasts, TV serials, . . . the list is endless. Their credibility as a source depends mainly on the scrutiny and the process their contents undergo before being published and also on the purpose, history, the ‘shelf life’ of their contents (archival or ephemeral), and the people behind them. Here are summaries of several major types of research sources often cited in papers.
Types of Research Sources
Peer-reviewed journals
At the top of the hierarchy are peer-reviewed journals, especially those with a high Impact Factor (a metric of prestige as determined by Clarivate Analytics and based on how often papers published in them are cited). The contents of these journals, mainly accounts of original research, are contributed by researchers, reviewed by experts, and copyedited by professionals. A subset of this category is review journals, the Annual Reviews series for example, which are also highly regarded although they do not publish original research. Because this category is the one with which researchers are most familiar, only a brief treatment is sufficient here, although a warning about “predatory journals” is essential.
Monographs
Although the more common term for this category is simply books, the term ‘monograph’ is used to emphasize that they are one-off products, setting them apart from ‘serials’ (a term favored by librarians), which are ongoing publications, published to a set schedule as a series of numbered volumes. The term ‘monograph’ also includes multi-author volumes and conference proceedings, the latter often falling midway between serials and monographs in the case of conferences held regularly, the proceedings of which are published as one-off books. Multi-author volumes are another subset, which take the form of one or more lead editors who conceptualize the volume and invite different specialists with expertise in different aspects of the theme topic to contribute chapters.
Reference books and manuals
Whereas the contents of peer-reviewed journals are often ‘works in progress,’ subject to revision in the light of ongoing research, the contents of reference books focus on permanence and authority, marked by universal acceptance, and represent a body of undisputed information that has stood the test of time. Each scientific discipline has its separate sources, such as the International Code of Nomenclature for Cultivated Plants used by plant taxonomists and the United States Pharmacopeia.
Trade journals
As types of research sources, what peer-reviewed journals are to scientists and researchers, trade journals are to practitioners and technicians. For example, Scientia Horticulturae is meant for researchers in horticulture; gardeners will find it of little interest and will probably prefer Horticulture, a trade journal. Trade journals typically focus on equipment, tools, implements, chemicals, etc.—the infrastructure of research rather than research itself. If at all these journals or trade sources are cited in research papers, the citations will be typically found in the ‘Materials and Methods’ section of the paper.
Popular science magazines
Midway between specialists or practitioners and lay readers are popular science magazines that seek to explain the complexities of science to the interested reader, the prime examples of such popular sources being Scientific American and New Scientist. The contributors to these magazines are typically professional writers or journalists, who read original research, interview their authors, understand the contents of research papers, and then write about the research using less technical language and bespoke (specially commissioned) illustrations. The articles can be demanding to read but are welcome by enthusiastic readers keen to advance their understanding and knowledge. The articles published in these magazines are unlikely to be cited in research papers because the articles are considered secondary sources, being themselves based on primary sources, namely research papers.
Newspapers and mass-market magazines
Newspapers and magazines enjoy the widest readership because they make the least demands on their readers in terms of not only prior knowledge and level of education but also time and motivation. They are truly for the masses. The purpose too is different, not so much to advance knowledge as to inform and entertain. The stories follow the pyramid structure beloved of journalists: the most essential information first, followed by a layer of important details, followed by a layer of background information and more details. And each story is typically heralded by an attention-seeking headline. All this makes newspapers and mass-market magazines (Reader’s Digest being a prime example) least likely to be cited in research papers as sources of support.
Websites, TV serials, podcasts, and other digital media
The sources mentioned earlier are essentially print sources at heart, although many journals have abandoned print altogether. However, their features, processes, motivation, target readers, etc. all reflect their origin in print. On the other hand, many sources are digital only, social media being the prime example: Instagram and Facebook have no print counterparts. The form, by itself, says little about the authenticity of contents one way or the other, which is why web pages are among the frequently cited sources even in research papers so long as the provenance of the contents can be easily ascertained. Remember also that most of such citations to web pages are in fact to research papers hosted on the website of the journal that published those papers, making them as credible as printed research papers.
Evaluating Sources
What makes some sources trustworthy and some sources dubious is not so much their form—analog (print) or digital—as the motivation, credibility, and processes of their publishers. Here is what to look for in deciding whether a given source is appropriate for being cited in scholarly works.
• Basis: original research and systematic reviews versus consensus versus second-hand accounts
• Motivation: advancing knowledge versus promoting informed understanding versus boosting circulation and entertaining
• Sources of income: subscriptions and article-processing charges or downloading fees versus membership dues (for journals published by professional societies) versus advertisements
• Shelf life of contents: archival or permanent (reference books and journals) versus several years or months versus weeks or days (even hours in the case of TV channels and radio broadcasts)
• Intended readership: academics and researchers versus subject enthusiasts versus lay readers
• Appearance (‘page gestalt’): staid design, dense text supported with tables, diagrams, graphs, footnotes, etc. versus more inviting but serious design, attractive illustrations, informative use of color versus attention-seeking design (huge fonts, splashes of color, photos of people), layout that varies from page to page, large advertisements, mix of typefaces and styles
• Language: serious and rich in jargon serving a specialist audience versus readable prose supported with examples, explanations, and educative illustrations versus elementary prose with limited vocabulary, less restrained language
Concluding Thoughts
Giving details of sources is a time-honored tradition in academic publishing, and the selection of sources says much about the selector (publishing in predatory journals and even citing them count against those who publish in them). Whereas the more traditional sources are clearly defined and conform to their category, digital publishing blurs the boundaries, and researchers are well-advised to scrutinize even the URLs (domains such as edu or ac versus com and org) and assess the credibility of authors and publishers before citing them.
