It is known that an essay is an alternation of theses and arguments proving them in a certain order. An excellent self-written paper contains, as a rule, several arguments to prove one thesis. And all this is aimed at confirming the hypothesis put forward by the author at the beginning of the work. Whether or not this is done is described in the conclusions. As you can see, this online class king review has a kind of circular structure.
Due to the absence of a wise experienced assistant, students usually just state their thoughts or limit themselves to a single argument to the hypothesis put forward in the introduction. Considering the essay to be a purely creative and non-serious work, they forget to indicate the list of references used.
Another no less common mistake is a trivial presentation of the opinion of other scientists on the issue under study. However, the essay is not only performed independently, it should contain the author's opinion, his personal view of the problem under study, the author's approach to explaining the reasons for its occurrence and solutions. This does not mean that you do not need to analyze scientific literature to write a paper. Without a clear understanding of the subject you are studying, your work will be meaningless. Expressing your erroneous, unscientific views is not an accomplishment or creative work. It is simply a fixed misconception on paper.