When to cite and when not to

What information should be cited? Where do I place the citation in a sentence? These two questions are commonly asked in my writing workshops. Other problems I regularly see are too many citations to support a piece of information or statements of fact made that should be supported by a citation. This blogpost reviews the basic concepts of citation and discusses the importance of always citing your sources.

What is a citation?

Authors of scientific documents use citation to indicate when information comes from another source: who wrote (or produced) the information being discussed and when it was published. 

The standard method of citation is to insert in-text citations directly before, or after, the information that is attributed to another author. These citations are then listed at the end of the document within either a bibliography or reference list. A reference list includes only the references that are cited, whereas a bibliography is both a list of the references cited and additional references used when researching and writing the document.

There are many different referencing styles, including the Harvard style which is commonly used in science publications. The Author – Date (Harvard) in-text citation is where the authors surnames and dates of publication are written within brackets at the end of a sentence or phrase. If there is more than one reference for a particular statement, the citations are separated by semicolons. For example: “Aquatic air breathers periodically break the water surface to gulp air but never leave water (Gonzales et al. 2006).” * (Magellan 2016). Alternatively, the authors surnames are used as the subject of the sentence to introduce their findings, while the date of publication is still written in brackets. In this case, the previous example could be rewritten as ‘Gonzales et al. (2005) found that aquatic air breathers periodically break the water surface to gulp air but never leave water’*.

Where should the in-text citation be placed?

I am often asked which is best, whether to place the citation at the end of the sentence, in brackets, or at the beginning, forming part of the sentence. As a general guide, if you use the findings of a study to develop your reasoning, it is easiest and more concise to place the citation at the end of the sentence. That way you can easily list more than one study as a list of citations in brackets. However, if you are discussing a particular study over more than one sentence, it is easier for the reader if you first introduce the authors as the subject of the sentence.

Hyperlinking is used with electronic publications to link a quote or citation directly to the document being cited, as with the Fensham et. al (2017) paper cited below.

Ideas, quotes and paraphrasing should be cited

You must include a citation if you quote, paraphrase or summarise someone else’s information or ideas. Quoting is writing the exact words used by another author and enclosing the text in double quotation marks; for example: Fensham et. al (2017) concluded that “The findings of the current study support the importance of rainfall variability as the major influence on the demography of E. melanophloia, the dominant tree in a semi-arid savanna” (p. 780). Paraphrasing is rewriting someone else’s writing using your own choice of words; for example, I would both summarise and paraphrase this previous quote as, ‘Fensham et. al (2017) concluded that rainfall variability is the major factor influencing the demography of E. melanophloia’ or ‘The demography of E. melanophloia is most strongly influenced by rainfall variability’* (Fensham et. al 2017). [Note that I used single quotes here to distinguish my wording and double quotes for the direct quotation].

Why do we cite?

The main reasons we cite is to clearly distinguish our work from others and so the source of information can be located and verified. Citation also honours the work or intellectual property of the author. Researchers most often cite other studies when developing their reasoning for their own studies, when comparing their work with other researchers and to indicate when authors reach similar or dissimilar conclusions. In this way, the citation process maintains and further develops the scientific discourse and shows how authors place their work within the published scientific literature.

What information can be cited?

It is a good idea to only cite information that has been published or made publicly available. Be cautious about referencing information from documents that are not publicly available or have not been peer-reviewed. Unpublished research is referred to as grey literature. Grey literature is defined as “…research that has not been published commercially and is therefore not necessarily searchable via the standard databases and search engines. Much grey literature is of high quality and can be an excellent source of up to date research in certain subject areas. Examples of grey literature: government reports, conference proceedings, theses / dissertations, research reports, maps, policy statements, clinical trials, technical standards, interviews and newsletters” (UNSW 2018). If it is necessary to cite unpublished information, the integrity of this information may come into question if no other sources are provided. Be cautious about generating conclusions or inferences solely on the basis of unpublished information.

How to cite different types of publications.

Most Australian university library websites will list guides to different referencing styles; for example Queensland University and Victoria University have in-depth guides on different referencing styles and how to cite and reference different types of publications.Also refer to Colin Neville’s book, The Complete Guide to Referencing and Avoiding Plagiarism (2016) for an in-depth guide on how to reference and cite a wide range of published material including books, papers, newspaper articles and audio-visual material.

What doesn’t need to be cited     

Scientific information that is commonly known to be true is not cited. Common knowledge is information that is widely accepted as being true and does not need to be cited. However, what is common knowledge depends upon the knowledge of the audience: what is commonly known to some groups of people would not necessarily be commonly known by another group of people. As readers, we trust that the author’s knowledge of what is commonly known is true. For example, my quote from Fensham (see above) included an unreferenced statement that E. melanophloia is a dominant tree in a semi-arid savanna (Fensham et al. 2017). I assume that this statement is common knowledge as it was uncited. Another example is that it is common knowledge to entomologists that (most) beetles have only one pair of flying wings, with the second pair of wings evolved to form protective covers to the flying wings. This fact would not need to be cited in entomology publications, not only because it is commonly known, but because it is easy enough to find out.

Avoid inadvertent plagiarism

If you continually make unreferenced statements, you can mislead the reader into thinking that your uncited information is either common knowledge or that you generated this information yourself. Remember that unreferenced statements can be considered plagiarism.

© Dr Marina Hurley 2018 www.writingclearscience.com.au