By Purpose:

• Basic Research: Expands knowledge without immediate practical application.
• Applied Research: Solves specific, practical problems.
• Evaluation Research: Assesses the effectiveness of programs or policies.
• Action Research: Addresses immediate problems within a specific setting.

By Method:

• Quantitative Research: Uses numerical data and statistical analysis.
• Qualitative Research: Explores complex social phenomena through methods like interviews and observations.
• Mixed Methods Research: Combines quantitative and qualitative approaches.

By Approach:

• Descriptive Research: Describes the characteristics of a population or phenomenon.
• Correlational Research: Examines the relationships between variables.
• Experimental Research: Manipulates variables to determine cause-and-effect relationships.
• Causal-Comparative Research: Examines the cause-and-effect relationships between pre-existing groups.

By Data Collection:

• Primary Research: Involves collecting original data.
• Secondary Research: Analyzes existing data.