School of Computer Science

Guidance Notes on Plagiarism

1. What is Plagiarism?

The Concise Oxford Dictionary defines plagiarise as:

"take and use another person's (thoughts, writings, inventions) as one's own."

A crucial phrase in this definition is "as one's own." In all learning at University it is completely acceptable to use another person's thoughts, writings or inventions to aid our own learning and understanding. Indeed, this is a primary method of learning. We all read textbooks, research papers, manuals and many other documents, and make use of the material contained in them. This is perfectly normal and acceptable.

The use of another person's work does not constitute plagiarism unless we present that work as our own. When writing essays, project reports, computer programs, or when giving any form of presentation, it is important that whenever we include the work of others, it is clearly acknowledged as such.

2. What is wrong with Plagiarism?

Plagiarism is a form of cheating. Copying the ideas or writings of others and presenting them as our own ideas and writings amounts to stealing some of the credit for another person's work and dishonestly obtaining credit for ourselves. Any form of cheating is to be condemned, and plagiarism is no exception. Theft of intellectual work by copying that work is still theft, and should be treated as such.

In a commercial or business context, the laws of copyright and patent are designed to help protect companies or individuals from the plagiarism of their work by others for commercial gain. In an academic context, there are no formal laws beyond those of copyright and patent, but the academic community works within very strong conventions that regard all forms of plagiarism as totally unacceptable and strongly to be condemned. Academics who are found guilty of plagiarism have their reputations and careers damaged or destroyed.

In a University undergraduate context, plagiarism is most serious when it occurs in work done for assessment. In assessing essays, project reports, computer programs, and all the other forms in which work can be presented, it is normally assumed that the work is entirely the student's own (except where the student has clearly stated otherwise), and the work is marked accordingly. If the submitted work is not entirely the student's own, then the credit obtained for it is not fully deserved.

Students are always expected to clearly acknowledge any use of other people's work in anything submitted for assessment. Unacknowledged use of the work of others is plagiarism. It is treated by the University as a very serious disciplinary offence, as for any other form of cheating. Likewise students must declare their own work if they submitted it previously at this or an other education institution.

3. Avoiding Plagiarism

Although you should take great care to avoid any possibility of being accused of plagiarism, this does not mean that you need to lock yourself away and avoid contact with all sources of ideas, etc. while you are doing a piece of assessed work. Quite the contrary! The properly acknowledged use of the work of others is a vital component of nearly all scientific writing and is in no way discouraged.

It is normal practice when writing essays, technical reports, etc., to borrow ideas and even the words of others. The important point, however, is that this must always be clearly and unambiguously acknowledged. If you incorporate into your work someone else's ideas or words so that they appear to be your own, it is plagiarism.

There are a variety of acceptable ways of acknowledging the work of others. Examples of some of the most common ways are given below.

Using References

Most often, it is the ideas rather than the exact words of another author that are copied. In such cases, a reference to the source of the ideas is appropriate. For example:

A good method for sorting the names into alphabetical order is the quicksort algorithm (Hoare, 1962). The algorithm works basically as follows. We firstly guess at a median value for the data to be sorted. Then we partition the data into two parts .....

The full reference should be given at the end of the essay or report, in a separate section headed "References." For example:

Hoare, C.A.R. (1962), "Quicksort", Computer Journal, Vol. 5, pp.10-15.

This refers to a research paper by C.A.R. Hoare, entitled "Quicksort" and published in the periodical Computer Journal. It is conventional in such references to give all the information included in this example: the author's name, the date of publication, the title of the paper (in quotation marks), the title of the journal (in italics), the volume number (in bold type) and the page numbers.

In references to books, the important information to include is: the author's name, the date of publication, the title of the book (in italics), and the publisher's name. If the information is taken from just a small part of the book, it may be appropriate to include page numbers as well. For example:

Knuth, D. (1968), The Art of Computer Programming, Vol. 2, Sorting and Searching, pp.211-217, Addison-Wesley.

Making Your Own Contribution Clear

It is important to make clear to the reader exactly what ideas are borrowed from elsewhere and what are your own. The example given above may continue:

Hoare's quicksort algorithm can be improved for the present problem by modifying the way in which the estimate of the median is computed ..... Our Java class SortedData uses this modified quicksort algorithm .....

This makes it clear to the reader that the student has contributed his or her own ideas: (i) by modifying the algorithm in the manner described, and (ii) by implementing the algorithm in the program for the class SortedData. Only the idea of the basic quicksort algorithm has been borrowed from elsewhere.

In general, if you make heavy use of material from textbooks and elsewhere when preparing work for assessment, how can you be sure that your own personal contribution is sufficient for you to be awarded a good mark? This question often worries students. The answer is very dependent upon the subject matter and other circumstances, so that it is not possible to give a short and simple answer here. Discuss it with your academic advisor or the course lecturers.

Direct Quotation

Direct quotation is not particularly common in scientific writing, as it is generally not the words that matter, but the meaning. Normally it is preferable to rewrite someone else's ideas in your own words, often changing the terminology and other superficial details to suit the new context.

However, in circumstances where it is appropriate to make direct use of the words of another person, those words should normally be included within quotation marks and a reference to the source of the words given in the usual way. For example:

A common theoretical approach to deadlock is that adopted by Magee and Kramer (1999), who define it as follows:

"Deadlock occurs in a system when all its constituent processes are blocked."

Although this definition is convenient for theoretical analysis of programs, from a practical point of view a much wider definition is more useful. So, instead, we adopt a definition in which deadlock is said to occur even if only a subset of all the processes are blocked, while the rest continue to run as usual. This situation is much more common in practice .....


Magee, J. and Kramer, J. (1999), Concurrency: State Models and Java Programs, Wiley, p.107.

4. Avoiding Plagiarism in Computer Programs

Almost all computer programs contain many ideas borrowed from elsewhere. Many also contain short sections of actual code copied from elsewhere. For example, writing a section of program to create a new window on screen with a menu at the top of the window is often done by simply copying a few of lines of code from an example in a programming manual or textbook, either with or without a few minor changes. This is normally regarded as fair use and typically requires no acknowledgement.

Any more significant copying of code from elsewhere should be acknowledged, however. The acknowledgement can be put in comments within the program itself. Reference to the source of the original material should be made in the same way as in essays or other documents (except that it may not be possible to use italics or other font variations). Obviously, it is not possible to put sections of code in quotation marks to indicate that they have been taken directly from elsewhere. Instead, the comments should make it clear which sections of code have been copied from elsewhere. Equally, the comments should make it clear when the basic method has been copied from elsewhere, but changes made to the details.

For projects: Because of the size of a software project, your report should always include a section that summarizes your sources. Say which parts of the software were your own original work, which were adapted from other sources, which were included as libraries and which were automatically generated. If that section is missing or unclear then your markers may be unable to award a mark. You will be called to meeting to clarify the sources, and it will also investigate the possibility of plagiarism.

5. Disciplinary Action

If plagiarism is found in work submitted for assessment, the action taken will depend upon the seriousness of the plagiarism.

For further information see our policy

6. Conclusion

In student work as in all other academic work it is important to carefully avoid plagiarism or anything that could be construed as plagiarism. The author of any piece of work is always assumed to be solely and totally responsible for that work unless it is clearly stated otherwise. Any and all use of the work of people other than the named author should be very clearly and fully acknowledged.

It is much better to play safe and have too many and too detailed acknowledgements than to omit them and risk being accused of plagiarism, which could result in a severe marks penalty and/or other disciplinary action.