The main task is writing the body of the essay, which should be presented in the form of a reasoned argument. The form of this varies with the subject of the essay but as the argument develops it should be clear to the reader what relevant evidence has been discovered, where/how it has been discovered and how it supports the argument. In some subjects, for example, the sciences, sub-headings within the main body of the essay will help the reader to understand the argument (and will also help the student to keep on track). In structuring their extended essay, students must take into consideration the expected conventions of the subject in which their extended essay is registered.
So, we need to think of the extended essay as a really long argument that you are having with yourself
First of all you have to explain to yourself the reason for having the argument in the first place. Why is the question that you are arguing about worth arguing about. To do this explanation you will have to take facts and information from sources but the important thing is that you will be putting them together into the explanation
Then you explain how you will have the argument, - how will you collect information to have the argument.
Then you present the evidence for the argument. There will be lots of citing and referencing here in many essays as you find out what other people have said or written about your question. However, it could be that you provide some of the evidence through surveys, lab work etc .
Then you analyse the evidence, weigh the opposing arguments, the strength of the evidence presented to decide what the answer is to the thing that you have been arguing with yourself over.
Then you decide how you could have a better argument with yourself next time .
Read back through what I have just written. All the places where you is written in bold type is your work. The argument is supported by the work of others but it is your argument
Once the main body of the essay is complete, it is possible to finalize the introduction (which tells the reader what to expect) and the conclusion (which says what has been achieved, including notes of any limitations and any questions that have not been resolved).
Any information that is important to the argument must not be included in appendices or footnotes/ endnotes. The examiner will not read notes or appendices, so an essay that is not complete in itself will be compromised across the assessment criteria.