Research designs vary based on the objectives, methods, and data collection techniques employed. Here are some different types of research designs commonly used across various disciplines:

1. Experimental Design: Experimental research involves the manipulation of one or more variables to observe the effect on another variable. It typically includes the use of controlled conditions and random assignment of participants to different groups. Experimental designs aim to establish causality.
2. Quasi-Experimental Design: Similar to experimental design but lacking random assignment, quasi-experimental research assigns participants to groups based on existing characteristics or conditions. It’s often used when random assignment is not feasible or ethical.
3. Descriptive Design: Descriptive research aims to describe phenomena or characteristics without manipulating variables. This design includes surveys, observational studies, case studies, and qualitative research. Descriptive designs provide insights into the prevalence, distribution, and characteristics of a phenomenon.
4. Correlational Design: Correlational research examines the relationship between two or more variables without manipulating them. It measures the degree and direction of association between variables. Correlational designs are useful for identifying patterns and predicting outcomes but cannot establish causality.
5. Cross-Sectional Design: Cross-sectional research collects data from a sample of individuals at a single point in time. It provides a snapshot of the population at a specific moment and can identify correlations between variables at that time.
6. Longitudinal Design: Longitudinal research follows the same sample of individuals over an extended period, collecting data at multiple time points. It allows researchers to observe changes over time, assess stability, and identify developmental trajectories.
7. Sequential Design: Sequential research combines elements of cross-sectional and longitudinal designs by collecting data from different cohorts at multiple time points. It provides insights into both age-related and time-related effects.
8. Case Study Design: Case studies involve an in-depth examination of a single individual, group, organization, or event. This design is particularly useful for exploring complex phenomena, contexts, or processes in real-life settings.
9. Action Research Design: Action research involves collaboration between researchers and practitioners to address specific problems or challenges in a practical setting. It emphasizes iterative cycles of planning, action, observation, and reflection to bring about positive change.
10. Mixed-Methods Design: Mixed-methods research combines qualitative and quantitative approaches within a single study. It provides a comprehensive understanding of a research problem by integrating different data collection and analysis techniques.

These are just a few examples of research designs, and researchers often select or adapt designs based on the specific objectives, context, and constraints of their studies. Each design has its strengths and limitations, and the choice depends on the research questions and goals.