Another important principle in technical writing is that the introduction should be problem-focused, giving the reader enough background so that the paper’s importance and relationship to key ideas are clear.
A rule of thumb about the introduction’s length: about 5-10% of the entire paper.
You should get your reader’s attention immediately by announcing the paper’s subject or by launching into a relevant scenario or narrative that informs or illustrates your overall argument.
A paper illustrating the costly effects of poor mine design, for instance, might open with the scenario of how a poorly designed pillar at a salt mine in Louisiana once collapsed, fracturing the surface above and draining an entire lake into the mine.
The first excerpt is from a paper on the generic nature of America’s highway exit ramp services; the second is from a paper on shape constancy. Our eyes often receive pictures of the world that are contrary to physical reality. Normally you will not devote a separate section of the paper to this; in fact, often the thesis or objective is conveniently located either right at the beginning or right at the end of the Introduction.
The observation struck me slowly, a growing sense of déjà vu. A pencil in a glass of water miraculously bends; railroad tracks converge in the distance. A good thesis statement fits only the paper in which it appears. ." Instead, concretely announce the most important elements of your topic and suggest your fundamental approach—even point us toward the paper’s conclusion if you can.
As examples of how creative an introduction can be, here are the opening lines from a geography paper and a paper on optics, both of which use narrative technique to arouse our interest.
Note how the first excerpt uses an "I" narrator comfortably while the second excerpt does not use "I" even though the writer is clearly reflective about the subject matter. Most papers have outright thesis statements or objectives.
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For all women, it is never too late to prevent osteoporosis or lessen its severity by making appropriate lifestyle choices.