For your dissertation you are required to collect information about a situation or problem which interests you, and to relate this to an analysis of the already-established body of knowledge in the chosen area. The information you collect constitutes your research data. In order to facilitate appropriate analysis, great care should be taken at the planning stage to ensure that the methods of data collection will enable you to address the specific questions which you have in mind.
Basically, the successful planning of your enquiry hangs upon being very clear about what you are trying to find out and why. Making sure that you have reasonable expectations about the possibility of being able to carry out the project is very important. Planning the collection and analysis of your data will involve you in constantly referring back to exactly what it is you are trying to find out.
With this in mind, you should expect to devote a considerable amount of time and thought to the selection of your methodology (approach) and particular research methods. You should make sure that you discuss a proposed outline of your methodological decisions with your supervisor at an early stage.
This will be an important aid in developing your research project.
You should also consult any research methodology texts referred to earlier in the programme which may focus specifically on research in your subject area. (On courses which include a module explicitly on Research Methods, you will have been provided with a bibliography which you should now revisit.).
All research, whatever the focus, raises serious ethical and moral as well as technical issues about how it is conducted. A number of researchers have written expressly on these kinds of issues (e.g. Halpin and Troyna, 1994). You may have come across some already during the programme but they are well worth re-viewing before you undertake any fieldwork.