The writer should keep the introduction simple. He should not complicate it so much that the reader gets confused about the project even before he comes to the main body of the report. Academic language should be used, but at the same time the content should be simple enough for even a layman to understand. The author needs to explain to the readers why the subject is important and what relevance it has to the related academic field. The goal of the project, what the author aims to prove through this body of work and why he undertook this endeavour should be explained in the introduction.
There are few dissertations which are completely original in nature. But chances are that most of them are an improvement of an earlier body of work or a variation of something that was investigated earlier. If this is so the author should make a reference to those earlier bodies of literature and explain how his project is an improvement of all the work that was done before. This will also help him avoid charges of plagiarism in case he has inadvertently used any material written by other authors.
One of the most important things that the author needs to keep in mind is that he should not include the conclusion, advertently or inadvertently, in the introduction. If he were to do this, then the whole point of writing the report and getting the author to read it would be lost. The whole idea of doing a project and writing it in a step by step manner is to tell the reader exactly what the researcher aims to prove, show how he has collected the data, write the analysis and finally put down his conclusions. In this regard it would be worthwhile if the writer were to put down in brief the research methodology behind the work that he has accomplished. It is essential for the report to start off on a good note; this way the reader would be tempted to continue reading the rest of the thesis.