i take it the exam/assigment question asks this rather than there is an actual site you want to contribute too? considering the first, i would write it just like writing study notes. i would write in a way to try to explain your ideas and concepts to others who already know the text.heilanglang said:
It's your choice. If you're referring to a past HSC question then this question should be open for varying text types. A "contribution" can be anything e.g. article, speech, essay etc. Most people go for the essay because it is easiest.