Using Numerical References in Your Thesis or Dissertation
If you are writing a thesis or dissertation in the medical or biological sciences, you will probably need to use numerical references such as those required for a Vancouver style of referencing. Numerical references are extremely easy to produce in running text, since in most cases all that is needed for each citation is a number, and they are certainly unobtrusive for readers, but this simplicity hides a significant potential for errors that must be carefully avoided while recording references in a numerical system.
For instance, numerical references can become problematic if a source is missed when the sources you use in your thesis or dissertation are numbered and added to your reference list. This is because numerical references are arranged in numerical order according to when they are first cited, so the first source cited in a text becomes reference 1, the second, reference 2, the third, reference 3 and so on. Each number is assigned to one source only and each source bears only one number, which it retains throughout a document. This means that if you miss a source while numbering your references and adding them to your list, the missing source will have to be numbered and added when the error is discovered, while all sources that follow it will need to be renumbered both in the main text and in the list. If, for example, you missed the third source you cited, it will need to be numbered 3 when it is added, and what was reference 3 will need to be renumbered as reference 4, what was reference 4 will need to be reference 5 and this will continue to the end of both your list and your document.
While it is always imperative to record every reference accurately in scholarly writing, this is nowhere more important than when you are using numerical references. If you miss a source, your numbering will be incorrect and your readers will be led to the wrong sources, a situation that misrepresents the work of your colleagues and predecessors and may well confuse and frustrate your mentors and examiners. Unless you happen to mention author names and publication dates in your discussion, your readers will not have the information they need to guide them to the correct sources as they would with other referencing systems.
The numerical order required in numerical references means that the best time to number and arrange your citations is when your thesis or dissertation (or perhaps each chapter of it) is virtually complete so that it is unlikely that changes altering the order of your references will take place. While the document is still in progress, you can use short tags (perhaps in parentheses or square brackets to separate them clearly from the rest of your text) such as author surnames, shortened titles, publication dates or whatever will efficiently lead you back to the correct sources. When you check your citations as you finish your work, which is always advisable, you can then remove these tags and number your references, adding them to your list in the correct order.
Whenever you directly quote a source, you should include a page number along with the reference number to indicate exactly where you found the passage. Your university or department may provide specific guidelines for theses and dissertations that include details about exactly how page numbers should be recorded. If so, these guidelines must be followed with precision and consistency, but if you are working without such instructions, the key is to distinguish page numbers from reference numbers, which can easily be done by using the abbreviation ‘p.’ (singular) or ‘pp.’ (plural) before the numbers that represent pages.
