Introductions are extremely important in essay writing. There are at least three good reasons for taking time to write a good introduction:
You never get a second chance to make a first impression. Your introduction is an important road map for the rest of your essay. Ideally, your introduction will make your readers want to read your essay. (Adapted from: www.unc.edu - introductions)
This is the part of the essay where you put the reader on the same wavelength. Research shows that you get most of your marks based on the first half of your answer. The reader wants to know that she/he is dealing with a student who has understood the question and engaged with it.
The reader also wants to know whether or not the student has taken the time and trouble to edit the writing to make sure that it’s coherent and doesn’t contain errors. They can learn all this from your introduction.
Remember that the reader might be reading thirty answers to the same question. How does he/she know how you have interpreted and approached the question? What should she/he expect from your answer? If you want to raise the sophistication of your answer to degree level you will avoid ‘I am going to...’ or even ‘This essay will...’. Ideally, try to phrase your answer in a way that will engage the reader in the topic and make them forget that you are a student writing an essay. For useful examples of introductory phrases go to: Manchester Univeristy - Phrasebank