This involves understanding what topic area the title refers to and what are you being asked to do with the information. Common faults with essays are that they cover the wrong topic or they fail to deal with the information in the way that was asked by the essay title. The next two sections will deal with each question in detail.
Titles are normally transparent as regards the general area that they concern.
Any ambiguities can normally be cleared up by talking to your tutor or the lecturer that set the question. It must be added that although the general area of the question is obvious, the relevance of the some of the information you gather may not be. It is part of the art of essay writing to decide what information should be used. For the example above, the focus of the essay should be on short term memory, but there could be some mention of long term memory to provide the contrast. It is important to know initially what is being asked by the question.