Where’s your information coming from?

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How to critically appraise the sources of your information

You’ve got that assignment, project or research topic. You’ve made some notes and thought about where to look for the information. You’ve gone to the library or started to search on the internet. But have you considered how to analyse the sources of your information? If you choose materials from an unreliable or questionable source, the content of that assignment, and all your hard work, might be for nothing.

Analysing a book as an information source

The Author

One of the first things to consider when you choose a book to use as an information source is the author. Look at the author’s background and qualifications and check to see whether this book (or journal article) is written on a topic which the author knows something about or is an expert on.

You should also try to establish whether the author is known. For example, has your teacher or lecturer mentioned this author? Or perhaps you have seen the author’s name in reading lists or cited in bibliographies.

Finally, you should check to see if the author is associated with a well-known institution or organization. Try and find out some information about the organization or institution.

Publication Date

One way of checking whether the information you are using is up-to-date or current is to look at the publication date of the book. Some areas of study outdate very quickly, especially areas in which there are rapid developments (such as in some fields of science or IT) or areas which rely on statistics and figures (such as Economics). Of course, for some areas of study, especially in the Humanities, it is possible to utilize materials written years ago without risking using materials which are out of date.

As well as looking at the publication date, you should also look at the edition of the book you are using. New editions often contain revisions, corrections and updated information so it is better to get hold of the latest edition available.


Of course, not every useful book will be published by a well-known publisher, but the publisher can be an indication of reliability when it comes to selecting a source. Books published by a university press are more likely to be scholarly. Well-known or reputable publishers are more likely to be a secure bet in terms of quality.


Now it is time to consider whether the content of the book is suitable for your purpose.  It is a good idea to read the preface or introduction in order to see what the author intends to cover.  It is also useful to look at the table of contents and the index so that you can get an overview of what is in the book. The bibliography and chapter headings can also help you to decide whether this book will be useful.

When examining the content of a book, you should ask yourself questions about the following points:

(i) Intended Audience

Ask yourself what type of audience the book was intended for. Is it aimed at a general audience, in which case the materials may be simpler, or is it aimed at a specific audience who may have specialized knowledge? In this case, the materials might be very technical or too advanced.

(ii)  Reasoning

It might depend on the subject area you are studying, but you should see whether the book you are using is covering fact or opinion. Facts should be verifiable while opinion, although based on factual information, may be someone’s interpretation of the facts. It is not always easy to distinguish fact from opinion as a skilled writer can often make their interpretations seem like facts.

Also, you need to consider the data, information or facts which are presented in order to decide if they are supported by evidence and have been researched. See if there are assumptions made or some omissions in the information.

Is the language quite objective or is it emotive? This might affect the way you respond to the materials or it might mean that it is biased in some way.

(iii) Sources

Does the information in the book use primary or secondary sources as a basis for their research and findings? And what are the sources? It is usually better to choose both primary and secondary sources if you can.

(iv) Other factors

Sometimes, the writing style of certain books might not suit you. Check to see if the text is easily accessible.

You might also be able to tell whether a book is going to be useful to you, or suitable for your purpose, by reading a review of the book. It should be possible to locate reviews of the book, or details on the author by using the internet.

And what about information on the internet?

Of course, in this day and age, not as much research is done using books as it once was. These days, a lot of people rely on information they find on the internet.  But how can you tell whether the websites you’re using for your research are reliable? 

Actually, a lot of the same considerations apply when surfing for information on the internet as when consulting a book in the library.

Think about the source

Is it a primary source? It is possible to get a lot of up-to-date data and statistics and other kinds of information directly from primary sources on the internet.  For example, government departments which have compiled information often have it available on their websites.

Consider whether the website has integrity.  Is it somehow associated with an institution or authority? Sometimes links also provide clues to this as a respectable or prestigious website is unlikely to trade or post links from sites which are unreliable.

Think about a possible bias. On the internet there are a lot of sites with a vested interest, often a commercial one. Consider what the vested interest might be when reading a website.

Citing and sources

Whether you’ve used books or the internet to do your research and write your project, paper or essay, do not forget to quote your sources. You might have to cite your sources in the body of your work, or it might be enough to simply add a bibliography.  But do make it clear where your information comes from – this protects you and shows the work and effort you’ve put into the research.

I find that a great part of the information I have was acquired by looking up something and finding something else on the way.
Franklin Adams 

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