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Critical Thinking and Writing: Presenting your Sources


An important element of critical writing is how you integrate, synthesise, evaluate and use supporting evidence. It is easy to fall into the trap of allowing your sources to stand alone in making a point for you or simply speaking for you. This guide, therefore, highlights some useful techniques for integrating sources in order to strengthen your criticality, ensuring that your voice is leading the argument and the evidence is back in its place of supporting you.

Using your Sources

One of the most important aspects of academic writing is making use of the ideas of other people. Those ideas offer the foundations and evidence for your writing.

There are several ways to report sources:

Quote if you want to use the author’s words;

Paraphrase if you want to keep similar length;

Summarise if you want to make the text shorter;

Synthesise if you need to use information from several sources. Synthesis is generally the preferable way to report sources, as it shows your authorship in creating a logical text, organised by topic, referring to the relevant sources, with a commentary on them.

In all cases you need to acknowledge the author’s work with references, or you will be plagiarising. 

How to Introduce Evidence

To properly introduce a source, follow those tips:

1) When quoting someone for the first time, remember to use their full name. After this, you can refer to them by their surname.

2) Express your voice by indicating to the reader whether you agree or disagree with a source, or are simply stating the evidence. You can for example vary the conjunction (as; although; despite...), preposition (according to; in line with; counter to...), reporting verb (states; claims; maintains; suggests; proposes; discusses...).


Look at the examples below and consider the words used. As a reader, would you think the writer is agreeing, disagreeing or simply neutral and stating what Smith says?

According to Smith "..."

As Smith points out "..."

Smith suggests that "..."

Although Smith claims that "..."

Direct Quotes

Quotations can be powerful and compelling, but should be sparse and careful lest making your writing fragmented and difficult to follow (unless you are undertaking textual analysis and need to directly cite a piece of writing). It is important to use quotations correctly, and the following tips can help you:  

  1. Before inserting a quote, make sure you understand what the quote means, the context in which it is said, and how it will apply to your own text.
  2. Always remember to introduce the quotation. Providing information, such as the author's name, the source of the quote, or a short summary, will help signpost the quotation and give a clearer indication of how the quote will be used in supporting your argument. 
  3. Use a variety of reporting verbs when introducing quotations. The way you introduce the quote will help orientate the reader to how you are interpreting and perceiving the quote. 
  4. As a rule of thumb, for quotations longer than three lines, separate these from the text, indent the whole quotation, remove quotation marks and make it single spaced. Anything shorter than this can remain within the text. 
  5. Make sure to discuss the quotation afterwards. The quote should never (or almost) stand alone as self-explanatory. Question what the quote means, what your view of it is and how it helps move your argument forward. 
  6. You can condense a quote by missing out words if it is not all relevant. Add [...] to indicate where the missing text of the quote should be. 
  7. Keep in mind that quotations are never meant to replace your own argument; they are merely there to support your argument. Do not allow them to stand in for your own voice. 


The marketing of luxury products is quite different to that of mass products. To begin with, the time frame is longer. As Kapferer and Bastien (2009, p313) aptly suggest, "one does not launch a luxury brand; one builds it progressively by managing the allocation of resources in a very specific way". For example, for luxury brands, advertising does not aim at immediate increases in sales; rather, it aims at fostering people's dreams, and the dreams can take years to turn into effective purchases of the advertised products. Therefore, luxury brands need a marketing strategy that considers the long term, rather than short-term gains. 


Paraphrasing is an effective way of using supporting evidence when we want to express the meaning of someone's work through our own words to achieve greater clarity. It is a useful way of demonstrating to your reader that you have understood the content of your supporting evidence and are able to translate another person's ideas into your own words. 

How to paraphrase

  1. Read and understand the section you wish to paraphrase.
  2.  Cover it up.
  3. Express verbally what you remember from the text. 
  4. Write down with your own words what you remember of the text. 
  5. Check the text to ensure you have reported the same meaning.
  6. If you need to add or amend anything, make sure you change the sentence structure and vocabulary of the original text (do not change specific, technical terminology).
  7. Make sure you reference the passage. 


Original text:

“But the sensation of roughness had almost entirely been ignored by scientists. Euclid, the Greek geometer whose Elements is the world’s oldest treatise with near-modern mathematical reasoning, focused on its opposite, smoothness. He and innumerable followers studied smoothness in exquisite detail. Lines, planes, and spheres are the matter of Euclidean geometry, as we are all taught in grade school. I love them; but they are concepts in men’s minds and works, not in the irregularity and complexity of nature” (Mandelbrot, 2008, p123-124).


Mandelbrot (2008, p123-4) points out that the perception of roughness has generally been overlooked by scientists. Starting with the Greek Euclid, a pioneer of mathematical reasoning, for centuries geometry has been focusing on smooth and neatly drawn figures. This is the geometry we still study at school and are all familiar with. However, those smooth, perfect figures hardly exist in nature, which instead is pervaded by rough, irregular shapes.


Summarising text provides an abridged, shorter version of the original text.  


Original text:

“But the sensation of roughness had almost entirely been ignored by scientists. Euclid, the Greek geometer whose Elements is the world’s oldest treatise with near-modern mathematical reasoning, focused on its opposite, smoothness. He and innumerable followers studied smoothness in exquisite detail. Lines, planes, and spheres are the matter of Euclidean geometry, as we are all taught in grade school. I love them; but they are concepts in men’s minds and works, not in the irregularity and complexity of nature” (Mandelbrot, 2008, p123-124).


Mandelbrot (2008, p123-4) points out that Euclidean geometry studies extensively the concept of smooth and smooth shapes, but does not deal with roughness, which is in fact most common in nature.

Video on Summarising and Paraphrasing

Video on summary and paraphrase by Doug Specht, Senior Lecturer at the Westminster School of Media and Communication.

Comparing Sources

Comparing and contrasting is an effective way to show critical thinking and analysis of supporting evidence, particularly when you then continue by drawing your own conclusions from the evidence.


Ball (2005) argues that TV of a violent nature can influence children’s behaviour. However, Smart (2006) states that behaviour improves when parents watch too.  It is possible to argue, therefore that...

Note that the writer proves her critical analysis by suggesting a conclusion. Alternatively, the writer could bring in a third comparison that perhaps suggests another possible outcome or piece of evidence that supports Smart or Ball.

To strengthen the writing further, the writer could relate the comparison back to the topic sentence of the paragraph, demonstrating to the reader why this evidence is relevant in relation to what they are trying to argue in this paragraph, or throughout the essay as a whole.


Synthesis is an important element of academic writing, demonstrating comprehension, analysis, evaluation and original creation. 

  • With synthesis you extract content from different sources to create an original text. While paraphrase and summary maintain the structure of the given source(s), with synthesis you create a new structure. 
  • The sources will provide different perspectives and evidence on a topic. They will be put together when agreeing, contrasted when disagreeing. The sources must be referenced. 
  • Perfect your synthesis showing the flow of your reasoning, expressing critical evaluation of the sources and drawing conclusions. 
  • When you synthesise think of "using strategic thinking to resolve a problem requiring the integration of diverse pieces of information around a structuring theme" (Mateos and Sole 2009, p448).
  • Synthesis is a complex activity, which requires an high degree of comprehension and active engagement with the subject. As you progress in higher education, so increase the expectations on your abilities to synthesise.

How to synthesise:

  1. Identify themes/issues you'd like to discuss. These ideas can come from the texts you are reading.
  2. Read each text and look for information on the themes/issues you'd like to discuss. 
  3. Ask: how does this text relate to others? Is it in agreement with other sources? Does it differ in its perspective? Is its supporting evidence holding up? 
  4. Write your synthesis with your own flow. 
  5. Put together sources stating the same point; distinguish sources presenting counter-arguments or different points. 
  6. Always provide the references.

The best synthesis require a "recursive process" whereby you read the source texts, identify relevant parts, take notes, produce drafts, re-read the source texts, revise your text, re-write... (Mateos and Sole, 2009)

What is good synthesis? 

The quality of your synthesis can be assessed considering the following (Mateos and Sole, 2009, p439): 

  • Integration and connection of the information from the source texts around a structuring theme.
  • Selection of ideas necessary for producing the synthesis.
  • Appropriateness of the interpretation, e.g. absence of incorrect content. 
  • Elaboration of the content. 


Original texts (fictitious):

Animal testing is necessary to save human lives. Incidents have happened where humans have died or have been seriously harmed for using drugs that had not been tested on animals (Smith 2008).  

Animals feel pain in a way that is physiologically and neuroanatomically similar to humans (Chowdhury 2012).  

Animal testing is not always used to assess the toxicology of a drug; sometimes painful experiments are undertaken to improve the effectiveness of cosmetics (Turner 2015)

Animals in distress can suffer psychologically, showing symptoms of depression and anxiety (Panatta and Hudson 2016).



Animal experimentation is a subject of heated debate. Some argue that painful experiments should be banned. Indeed it has been demonstrated that such experiments make animals suffer physically and psychologically (Chowdhury 2012; Panatta and Hudson 2016). On the other hand, it has been argued that animal experimentation can save human lives and reduce harm on humans (Smith 2008). This argument is only valid for toxicological testing, not for tests that, for example, merely improve the efficacy of a cosmetic (Turner 2015). It can be suggested that animal experimentation should be regulated to only allow toxicological risk assessment, and the suffering to the animals should be minimised.  

Doug Specht, Senior Lecturer at the Westminster School of Media and Communication, explains synthesis for us in the following video. 

Evaluating Evidence

An essential element of critical thinking, reading and writing is to evaluate the evidence you encounter. The basis of the evaluation can be, for example, the validity, reliability, methodology, date of the study in question. 


Smith and Fry (2020) label online learning at the University of Ketchup as a success. However, their conclusions are based on interviews with teaching staff and the University management. The authors failed to investigate the students' views on online learning at the University. Therefore, a major measure of such purported success was not considered by Smith and Fry's study. 

In this example, the writer has considered the study carried out by Smith and Fry and suggests a limitation to the study's methodology that may have caused biased results. By suggesting a limitation, the writer has not taken the study for granted, accepting the results without critically analysing and questioning the validity of the study. 


Bottomley, J. 2015. Academic Writing for International Students of Science, London: Routledge.

Kapferer, J. and Bastien, V. (2009). The specificity of luxury management: Turning marketing upside down. Journal of Brand Management, 16(5-6), pp.311-322.

Mandelbrot, B. and Hudson, R. (2008). The (Mis)Behaviour of Markets. London: Profile Books.

Mateos, M. and Solé, I. (2009). Synthesising information from various texts: A study of procedures and products at different educational levels. European Journal of Psychology of Education, 24(4), pp.435-451.