Think of your study as a journey searching for gold. You are now the researcher who wants to find the gold, which is the truth about a specific topic. When you search for gold, you have a few milestones that you have to achieve. You will have to check with the previous literature of where the gold is. Maybe check the map to the hidden treasures. You may want to see what previous researchers have done. You want to cite everyone who has searched for the same gold and provided valuable findings to help you find the gold. This is your literature review.
Once you have learned from the literature that your gold lies in a particular place, then you will need to get the tools necessary to find that gold. You will need to establish your methodology that is going to be your tool to find the truth about this universe. The tools used to get gold may include a metal detector that will beep every time you find any type of gold. This tool may be helpful especially when you know that gold tends to be close to other metals as explained by the literature review.
Another methodology to find the gold is to ask the proper people who live or operate within the geographical place you are investigating. Questions that are relevant to gold finding, such as “have you heard of the availability of gold in this area?” This can be an example of how interviews work. You are trying to explore the area and you may want to ask the people around that area about their opinion. Now, their opinions may not really matter. You may already know that they do not know the answers. If they did know, maybe they have already found it. In our context, there must have been papers about it already.