Determine the Purpose
Most times you'll be presented with a question to be investigated, but if you're just given a general topic, always try to narrow the focus and choose an area that interests you (and one that has plenty of resources). For example, if the topic is "Inventions," narrow the focus to a particular field such as inventions in medicine,transportation, or communication.
The first thing to note is that you always have a specific purpose when you write a report, and this makes it easy to start — at least you know where you're meant to be going. To determine your purpose, ask yourself the following questions:
Why am I writing this?
To answer this question, you should determine:
What specific information do I require?
Do I need to explain known facts?
Have I been asked to analyze a situation or recommend a particular line of action?
Do I need to review a course of action?
What do I want to achieve?
To answer this question, you should determine:
Is the report meant to generate an action?
How persuasive should I be?
Do I need to come to a conclusion or make a decision about a specific matter?
The "Purpose Sentence"
This is where you state your reasons for preparing the report; it can be written as either a statement or a question. Spend some time composing your purpose sentence, and use these examples as a guide:
To investigate the link between kelp beds, pollution levels, and loss of fish stocks in X. (statement)
What are the psychological causes of obesity? (question)