Qualitative research: A method of inquiry used in social sciences and humanities that focuses on understanding human behavior, beliefs, experiences, and interactions through non-numerical data such as interviews, observation, and textual analysis. Quantitative research: A research method that focuses on collecting and analyzing numerical data to identify patterns, relationships, and trends in a systematic and objective way. It is commonly used in fields such as psychology, economics, and epidemiology. Mixed methods research: An approach that combines both qualitative and quantitative research methods in a single study to provide a more comprehensive understanding of a research problem or question. Case study research: A method of qualitative research that involves an in-depth exploration of a particular individual, group, or event to understand and analyze its complexities and context. Experimental research: A research method in which the researcher manipulates one or more variables to determine their effect on a dependent variable, typically conducted in controlled laboratory settings to establish cause-and-effect relationships. Longitudinal research: A study design that involves collecting data from the same sample or group of individuals over an extended period of time to observe changes, developments, or trends over time. Survey research: A method that involves collecting data from a sample of individuals through structured questionnaires or interviews to gather information about their attitudes, opinions, behaviors, or characteristics.