Overview
This lecture provides a brief overview of the four main types of quantitative research: descriptive, correlational, experimental, and quasi-experimental designs.
Descriptive Research
- Focuses on describing the "what" of a phenomenon, not the "why."
- Aims to present the status or characteristics of a variable or situation.
- Involves data collection mainly through observation.
- Researchers create hypotheses after data collection, not before.
- Cannot determine cause-and-effect relationships.
- Useful for defining characteristics, comparing groups, measuring trends, and validating conditions.
Correlational Research
- Measures and analyzes the statistical relationship (correlation) between two variables.
- Neither variable is manipulated by the researcher.
- Examines if a relationship exists and its strength and direction (positive or negative).
- Cannot establish causality, only association.
- Used when experimentation is impractical or impossible.
Experimental Research
- Also called true experimentation; establishes cause-and-effect relationships.
- Researchers manipulate one or more independent variables and control or randomize other variables.
- Uses the scientific method for systematic investigation.
- Commonly used in sciences such as psychology, sociology, biology, and medicine.
Quasi-Experimental Research
- Resembles experimental research but lacks full experimental control.
- The independent variable is manipulated, but there is no random assignment of participants.
- May lack a control group, random selection, or active manipulation.
- Seeks to establish causal relationships but with some limitations compared to true experiments.
- Often called causal-comparative research.
Key Terms & Definitions
- Descriptive Research — Aimed at describing characteristics or status of a subject without seeking causes.
- Correlational Research — Studies the relationship between two variables without manipulation.
- Experimental Research — Investigates cause-and-effect by manipulating variables in controlled conditions.
- Quasi-Experimental Research — Similar to experimental research but lacks elements like random assignment; investigates cause-effect with some constraints.
Action Items / Next Steps
- Review related video lectures for more details on quantitative research and its characteristics as listed in the provided resources.