Research can be categorized into various types based on different criteria. Here are some common types of research:

1. Basic Research: Also known as pure or fundamental research, this type aims to expand knowledge and understanding of fundamental principles and theories without any immediate practical application.
2. Applied Research: This type focuses on solving specific problems or addressing practical concerns. It aims to produce findings that can be directly applied to real-world situations.
3. Quantitative Research: Involves the collection and analysis of numerical data to quantify relationships, patterns, or trends. It often uses statistical methods to draw conclusions and generalize findings.
4. Qualitative Research: Focuses on exploring and understanding phenomena through observation, interviews, focus groups, or textual analysis. It seeks to uncover meanings, motivations, and subjective experiences.
5. Experimental Research: Involves manipulating variables and observing their effects to establish cause-and-effect relationships. It typically involves controlled settings and random assignment of participants to different conditions.
6. Descriptive Research: Aims to describe characteristics, behaviors, or conditions of a particular population or phenomenon without manipulating variables. Surveys, observational studies, and case studies are common methods used in descriptive research.
7. Exploratory Research: Conducted when a topic is relatively new or not well understood. Its purpose is to gain insights, generate hypotheses, and identify potential variables or relationships for further investigation.
8. Explanatory Research: Seeks to explain why certain phenomena occur by examining the relationships between variables and identifying underlying causes or mechanisms.
9. Cross-sectional Research: Involves collecting data from a single point in time to examine relationships or differences among variables within a population at that specific moment.
10. Longitudinal Research: Involves collecting data from the same individuals or groups over an extended period to study changes or developments in variables over time.
11. Action Research: Focuses on addressing specific problems or challenges within a practical context, often in collaboration with stakeholders, and aims to bring about positive change or improvement.
12. Review Research: Involves synthesizing and analyzing existing literature, research studies, or data to provide a comprehensive overview, critique, or summary of a topic or field.

These are just some of the types of research, and often, research projects may incorporate elements of multiple types depending on the research questions, goals, and methodology.