A good introduction often signals to your reader that you are really in control of the subject matter. Thats worth doingit makes you more trustworthy and it makes the essay easy to read. There are a number of factors, however, that influence writing one:
A common strategy is to pose a problem or show a gap. Heres one students model: he uses 2 paragraphs. One introduces a problem, the next gives the focus or thesis of the essay and the source hes consulted:
Many of us are concerned with the present state of the environment. Problems seem to crop up faster than we can deal with them. Even worse is the fact that, despite our increasing understanding of how industrial society is destroying the environment, we persist in practices known to damage the natural balance of the earth. Many look to modern science and technology as the keys to an eventual solution. For others, it is modern science and technology that are at the root of the problem.
There has been, for some time now, an increasing school of thought that points to western/masculinist thought as the means of the environments eventual demise. They suggest that a closer understanding of western paradigms concerning issues of ecology and gender will reveal the inconsistencies and dangers of the practices they advocate. Vandana Shiva, a former physicist, is one such person. In her book, Staying Alive, she puts forth arguments suggesting that any solution to the growing environmental crisis must be found outside of the western/scientific model.
Note that he explains Vandana Shivas point of view, mentions the book itself, and presents his thesis in the 2nd paragraph. Too often students either omit the sources theyve consulted, or they cite them too early in the paper, not allowing for their own voice.