Overview
This lecture explains quantitative research designs, their classifications, purposes, and key features, focusing on descriptive, correlational, and experimental designs.
Quantitative Research Designs: Overview
- Research design is a strategy that integrates study components to address the research problem.
- It serves as a blueprint for data collection, measurement, and analysis.
Types of Quantitative Research Designs
- Three main classifications: descriptive, correlational, and experimental research designs.
Descriptive Research Design
- Used to observe and report phenomena, behaviors, or traits as they occur.
- Data collected via tools like rating scales and questionnaires (e.g., Likert scales).
- Does not establish causal relationships; focuses on describing variables.
- Best suited when little is known about the topic or for exploratory studies.
- Types: observational methods (documenting behaviors), case studies (in-depth study of individuals/groups), and survey research (administering surveys).
- Survey research types: cross-sectional (data at one time point for comparison) and longitudinal (data collected over multiple time points).
- Examples: Describing students’ summer activities, tobacco use in teens, attitudes about school years.
Correlational Research Design
- Determines the extent of relationship between two or more variables, not cause and effect.
- No experimental manipulation; variables are measured as they are.
- Example: Relationship between intelligence and self-esteem, or between diet and anxiety.
- Common data collection: questionnaires, tests, observations.
Experimental Research Design
- Tests if a variable (treatment) influences an outcome; establishes possible cause-effect relationships.
- Two types: true experiments (random assignment to groups), and quasi-experiments (no random assignment).
- Structure involves pre-test, treatment (for experimental group only), and post-test for both groups.
- Examples: Comparing effects of cooperative group strategy vs. lecture on achievement.
Key Terms & Definitions
- Research Design — Blueprint for collecting, measuring, and analyzing data in a study.
- Descriptive Research — Design that observes and reports phenomena without establishing causality.
- Correlational Research — Design studying relationships between variables without cause-effect claims.
- Experimental Research — Design testing cause and effect by manipulating variables.
- Cross-sectional Survey — Survey collecting data at a single time point.
- Longitudinal Survey — Survey collecting repeated data over time from the same or similar populations.
- True Experiment — Participants are randomly assigned to experimental/control groups.
- Quasi-Experiment — No random assignment; groups are selected.
Action Items / Next Steps
- Review examples of each research design.
- Identify which research design best fits your own study topic.
- Prepare for upcoming discussions on data collection methods.