Mixed Method Research makes use of both qualitative and quantitative methods and is used for the scenario when either one of these will not suffice. Quantitative methods deal with objective questions like how many and how much, which are answered with a numerical value or a parameter. Qualitative methods deal with subjective questions like why, what, etc.—aspects related to respondent's opinion and views.
Many a time either of these techniques alone will not yield the desired results. In such a case, mixed method research is adopted. Many of the questions dealt with by researchers today require decision making based on a combination of results. An example could be deciding on whether to make a dam at a particular site. This will involve quantitative data about the design and advantages/disadvantages, while also including the perceptions of the affected population.