What sort of evidence should I use?



Many types of university assignment are persuasive or critical. In these types of texts, you are expected to argue a point of view, propose your interpretation of the data, recommend an idea or action, and/or evaluate the ideas of others. Whenever you are writing persuasively or critically, you need to provide evidence to support your claims.

Different disciplines use different types of evidence – e.g. arts and humanities disciplines often refer to published sources as their main evidence while science disciplines often use various types of empirical data (such as statistics or other experimental results) as their main evidence. It is also common to use more than one kind of evidence in a text – for example, the science disciplines frequently use both references to published sources and empirical data as evidence, often in different parts of the text.

In addition to finding the right kind of evidence, you need to evaluate the quality of evidence: not all pieces of evidence will be equally valuable for you to use. The first thing to consider is whether the evidence directly demonstrates support for a claim you are making – e.g. by showing that another scholar agrees with your claim, or that the results confirm your interpretation, etc.

The second thing is to consider how reliable the evidence is – e.g. Is it published in a peer reviewed journal or a book by a reputable publisher? Is the author someone who has expertise and status in the field? Have the data been obtained through a rigorous methodology, using an appropriate sample? etc.

Thirdly, individual disciplines have different values about good evidence: for example in some disciplines, such as Information Technology, sources may need to be quite recent, as publications which are 2 years old may already be out of date, while in other disciplines, like Philosophy, sources which are more than 200 years old may be authoritative and relevant.

If you are not sure what type of evidence is needed for a specific task, or what is good quality evidence in your discipline, you could start by:

  • Checking the assignment instructions and any rubrics/marking guide/grade descriptors provided
  • Asking your lecturer/tutor for more information
  • Discussing with other students
  • Looking at the type of evidence used in the readings for that unit of study

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