Firstly, you should understand that the purpose of a dissertation introduction is not to defend or attack a particular viewpoint, but to consider the question from all angles. On the other hand, you should clearly state your own position and demonstrate individual thinking. But you should not hold an extreme position or express exaggerated claims. If necessary, question the validity of prior findings, reject settled opinions, and reveal controversies concerning the issue you analyze; however, any criticism should be mild and unbiased. Keep in mind that it is always better to suggest something new than turn to explicit criticism.
A dissertation introduction should be free of any slang expressions or jargons. As you conduct a scientific research, do not go beyond the accepted language norms. You should remember that those who will read your dissertation introduction may be unfamiliar with your topic; thus, you should write an essay in an hour in a manner that will be understood by both an amateur and professional. Use a rigorous language yet easily comprehensible; avoid ambiguity and find the way to reconcile diverse aspects of the analysis. In addition, you should provide unequivocal definitions of specific notions employed in a dissertation introduction.
Do not write an extensive dissertation introduction; instead of focusing on a length, make sure that you have covered all necessary aspects. You should keep a balance between simplicity and complexity; do not go from one extreme to another. Each argument in your dissertation introduction should be well grounded and be linked to a certain theoretical concept; otherwise, these arguments may be regarded as spurious and inaccurate. If you suddenly realize that one of your arguments is flawed, substitute it for a correct one. Of course, it is difficult to foresee all drawbacks, but try to bring your dissertation introduction to perfection. When you use direct quotes, you should put them in brackets and necessarily indicate a page number. The widespread referencing styles for dissertations are MLA, APA or Harvard; however, your university may set other style and structural requirements.
Unquestionably, a smooth and consistent dissertation introduction will increase your chances of successful completion of a dissertation. It does not matter whether you employ the mentioned guidelines partly or entirely; anyway, the results will be striking and really surprising. Do not be afraid to experiment with different writing strategies or explanatory techniques, and you will soon find out that you have taken a giant step forward in understanding the main concepts of writing and researching.