An introduction should do at least four main things:
- i. Show that you have understood the title and what you are being asked to do.
- ii. State your objectives in the essay i.e. say what you are going to do.
- iii. Outline which aspects of the subject you are going to deal with and how.
- iv. Indicate what you are going to argue.
Another way of thinking about the introduction is that it should draw a map for the reader. Imagine you are taking the reader on a journey. Your introduction tells the reader not only the intended final destination but the route you are going to take, the method of transport, the places you are going to visit on the way, the people you are going to meet and even some of the things they are going to say.
If you can write an introduction like this then it will do a number of things. It will show the reader you have understood the question. It will show the reader you can think in an ordered, logical manner. It will show the reader that you know your subject. For every essay title there are things that tutors will expect to see mentioned. So if you can say ‘This essay will look at X using the theories of Professor Bloggs’, the person marking it is already interested.
Finally, drawing a map for the reader means drawing one for yourself. If you can say clearly what you are going to do then all you’ve to do is – do it!
Some things an introduction can do
Present an overview of the essay’s subject e.g. ‘Scientific paradigms in psychology were first theorised in…’
Set out the main idea of the essay.
Outline how the essay title will be interpreted.
Define important terms e.g. ‘This essay will use Professor Bloggs’s definition of X which states that…’
Explain the methodology to be used in the essay and why it’s being used.
Outline the issues to be explored in the essay.
Quote from another writer to get the reader’s attention and give an idea of what the essay is about e.g. ‘This statement is typical of a large number of writers who attempt to define the impact of globalisation because…’
You may be able to add some of your own to the list.
Different essays need different introductions
There’s no single form for an introduction. Different types of essays may require different types of introduction. Different subjects may follow particular conventions for written work. A social science or psychological study of a group of people may start with details of the research sample. A long essay or dissertation may start with a literature review. Your tutor may even tell you not to waste time on elaborate introductions. Nonetheless, the reader does need to have some idea of where your essay is going to take them and what you are trying to achieve in it.
First things last?
All this implies that you have to write your introduction first but you don’t have to. You should certainly start out with a clear idea of what you are going to do but this can be in draft or note form. After all, you may start out thinking you are going to use the theories of Professor Bloggs and then, halfway through writing, come across the theories of Professor Smith which cast an interesting new light on your subject.
In fact, the ideal time to be thinking about your introduction is when you’ve finished writing your essay. If that sounds odd then think about this: a common problem with student essays is that they have introductions that announce X, Y and Z and then don’t do them. So always check your introduction against your essay. You’ve said everything you want to say and you’ve got your essay into a form you are happy with. Have you followed your own map? Do you need to add or remove a few things here and there? Or do you need to draw a new one?
Here are some sample beginnings of introductions:
-  This book is about writing university assignments at degree level. One of the main reasons why we decided to write this book was that we wanted to help students find ways of putting writing at the centre of their learning.
Phyllis Crème and Mary R. Lea, Writing at University
-  Salman Rushdie once gave a lecture called ‘Is Nothing Sacred?’ in which he famously described literature as like a voice-room, a place where a number of conflicting voices discuss the world in which we live.
Rebecca Stott, Tory Young and Cordelia Bryan, Speaking Your Mind: Oral Presentation and Seminar Skills
-  Writing is a craft – and a difficult one. Whether a writer is writing a novel or a set of instructions for assembling a futon, the words s/he chooses to assemble into sentences will have to be drafted and drafted again.
Rebecca Stott and Simon Avery, Writing with Style