Things NOT to do in an introductory paragraph:

• Apologize. Never suggest that you don't know what you're talking about or that you're not enough of an expert in this matter that your opinion would matter. Your reader will quickly turn to something else. Avoid phrases like the following:
  In my [humble] opinion . . .
  I'm not sure about this, but . . .
• Announce your intentions. Do not flatly announce what you are about to do in an essay.
  In this paper I will . . .
  The purpose of this essay is to . . .
  
  Get into the topic and let your reader perceive your purpose in the topic sentence of your beginning paragraph.
• Use a dictionary or encyclopedia definition.
  According to Merriam-Webster's WWWebster Dictionary,
  a widget is . . .
  Although definitions are extremely useful and it might serve your purpose to devise your own definition(s) later in the essay, you want to avoid using this hackneyed beginning to an essay.
• Dilly-dally. Get to it. Move confidently into your essay. Many writers find it useful to write a warm-up paragraph (or two, even) to get them into the essay, to sharpen their own idea of what they're up to, and then they go back and delete the running start.

Writing an introduction

The abstract is the only text in a research paper to be written without using paragraphs in order to separate major points. Approaches vary widely, however for our studies the following approach can produce an effective introduction.

• Describe the importance (significance) of the study - why was this worth doing in the first place? Provide a broad context.
• Defend the model - why did you use this particular organism or system? What are its advantages? You might comment on its suitability from a theoretical point of view as well as indicate practical reasons for using it.
• Provide a rationale. State your specific hypothesis(es) or objective(s), and describe the reasoning that led you to select them.
• Very briefy describe the experimental design and how it accomplished the stated objectives.

Style:

• Use past tense except when referring to established facts. After all, the paper will be submitted after all of the work is completed.
• Organize your ideas, making one major point with each paragraph. If you make the four points listed above, you will need a minimum of four paragraphs.
• Present background information only as needed in order support a position. The reader does not want to read everything you know about a subject.
• State the hypothesis/objective precisely - do not oversimplify.
• As always, pay attention to spelling, clarity and appropriateness of sentences and phrases.