For more information, view the Scholarly Communications: Research Methods page
A research design is a strategy for answering your research question using empirical data. 
Creating a research design means making decisions about:
Your overall aims and approach
The type of research design you’ll use
Your sampling methods or criteria for selecting subjects
Your data collection methods
The procedures you’ll follow to collect data
Your data analysis methods
A well-planned research design helps ensure that your methods match your research aims and that you use the right kind of analysis for your data.
You might have to write up a research design as a standalone assignment, or it might be part of a larger research proposal or other project. In either case, you should carefully consider which methods are most appropriate and feasible for answering your question. (Source: Scribbr)
Designing your research methodology
Finding resources to answer your research methods and statistics questions can be challenging. Find out about the tools available to help you develop a well-planned research design to ensure that your methods match your research goals and that you use the right kind of analysis for your data. Furthermore, learn how to conduct ethically sound research while building a compelling case study or report.
Case Study: A case study is a detailed study of a specific subject, such as a person, group, place, event, organization, or phenomenon. Case studies are commonly used in social, educational, clinical, and business research. (Source: Scribbr)
Correlational: Correlational research is a type of non-experimental research method in which a researcher measures two variables and understands and assesses the statistical relationship between them with no influence from any extraneous variable. (Source: QuestionPro)
Cross-sectional: A cross-sectional study is a type of observational research that analyzes data of variables collected at one given point in time across a sample population or a pre-defined subset. (Source: QuestionPro)
Descriptive: Descriptive research refers to the methods that describe the characteristics of the variables under study. This methodology focuses on answering questions relating to “what” than the “why” of the research subject. The primary focus of descriptive research is to simply describe the nature of the demographics understudy instead of focusing on the “why”. (Source: Voxco)
Ethnographic: Ethnographic methods are a research approach where you look at people in their cultural setting, with the goal of producing a narrative account of that particular culture, against a theoretical backdrop. (Source: Sage publishing group)
Experimental: Experimental research is research conducted with a scientific approach using two sets of variables. The first set acts as a constant, which you use to measure the differences of the second set. Quantitative research methods, for example, are experimental. (Source: QuestionPro)
Explanatory: Explanatory research is a method developed to investigate a phenomenon that had not been studied before or had not been well explained previously in a proper way. Its main intention is to provide details about where to find a small amount of information. (Source: QuestionPro)
Exploratory: Exploratory research is defined as a research used to investigate a problem which is not clearly defined. It is conducted to have a better understanding of the existing problem, but will not provide conclusive results. For such a research, a researcher starts with a general idea and uses this research as a medium to identify issues, that can be the focus for future research. An important aspect here is that the researcher should be willing to change his/her direction subject to the revelation of new data or insight. Such a research is usually carried out when the problem is at a preliminary stage. It is often referred to as grounded theory approach or interpretive research as it used to answer questions like what, why and how. (Source: QuesionPro)
Longitudinal: A longitudinal study is a research conducted over an extended period of time. It is mostly used in medical research and other areas like psychology or sociology. (Source: QuestionPro)