Choosing the correct method depends on your research question and your aim. Do you want to describe something, explore new questions or do you want to confirm a hypothesis? Answering this question first will be of key importance when choosing methods for your research project. Another factor to consider and heavily linked to the first question raised above, is asking yourself what kind of research you want to carry out. The question then is whether you want to use a deductive or an inductive approach.
Deductive: This term simply means that you start with a theory from which you develop a hypothesis, based on which you choose your research methods. In your research you then seek to confirm or disprove your hypothesis. This research approach is associated with quantitative data.
Inductive: In contrast to deductive reasoning, using an inductive approach means that you start with observations without having either a hypothesis or a theory guiding your research. The goal of inductive research is to let the hypothesis and theory emerge through the research you do. The idea is that you start your research with a clean slate in terms of theoretical expectations. This is of course very difficult, if not impossible, as we are always influenced by the things we experience and we often can’t help but have preconceived ideas of things, people and social phenomena surrounding us. Nonetheless, the challenge is to block this out as much as possible and to let the theory emerge from the observations you make. This kind of approach is strongly associated with qualitative data.
As you can guess from the above differentiation, often there lies a large ideological gulf between these two approaches that is also reflected in the question what kind of data you should collect. The key difference lies in quantitative and qualitative data.
Quantitative Data: Basically, quantitative data are numerical data that allow you to measure and quantify things and to test hypotheses. Most typically you will collect quantitative data through questionnaires with closed questions and scales. This means that the participant can only select pre-given answers which have an assigned numerical value for later analysis. Alternatively, they may be asked to select a numerical value on a scale that represents a certain answer e.g. Strongly disagree =1, Strongly agree = 5. These types of scales are called Likert Scales. Quantitative data have long been seen as the only valid sort of data in scientific research, but this perception has been eroded as the collection of qualitative data has become more widely accepted and used, especially among social scientists.
Qualitative Data: When you collect qualitative data you try to understand meanings and interpretations. The idea is to collect narratives of research participants, to be more detailed and holistic, and to account for contextual circumstances. This kind of data may be made up of words, direct observations, videos, texts, pictures etc. and will be most typically collected using interviews, focus groups or observational techniques.
The distinction between quantitative and qualitative data seems very clear and hard, yet numerical data always has a qualitative and subjective element to it and qualitative data can be quantified as well, e.g. through textual analysis that counts words. If you are interested in a more detailed discussion of this ideological divide, have a look here: http://www.socialresearchmethods.net/kb/datatype.php
In fact overcoming this gulf can actually be very fruitful and more and more researchers, including myself, discover the beauty of using mixed methods. A mixed methods approach allows you to collect both quantitative and qualitative data and benefits from the advantages of both types of data while offsetting, at least to some extent, the disadvantages of either. In addition it makes your final thesis and interpretations stronger as you rely on multiple sources of evidence, not just a single one. An often used term to describe this advantage is data triangulation.
The Difference between Methods and Methodology
This question is another thing that bothers many students that are confronted with it for the first time and often teachers fail to give a simple answer to this question. The problem is it is not easy to answer this question in simple terms but I will try to answer it in the way I have learned to understand the difference over the years. For me Methodology is the overall approach I am using to develop a research project and Methods are the techniques I utilize as part of this approach. Methodology requires you to understand your research aim and question first and to have a good understanding of the different ideologies that may guide this research. This understanding will then allow you to choose the best methods to accomplish your goals.
So in the most basic and reductionist sense:
Methodology = the why
Methods = the how
The above discussed terms are only a starting point in understanding the research process in the social sciences but sometimes just getting a basic understanding of some complicated sounding words can open a new world of exciting research opportunities for you.