The main types of quantitative research, as identified in the provided reference, are Descriptive, Correlational, Causal-Comparative/Quasi-Experimental, and Experimental Research.
Quantitative research is a systematic way of investigating phenomena by gathering quantifiable data and performing statistical, mathematical, or computational techniques. It aims to measure, test, and find relationships between variables.
Based on the provided reference, here are the four main types:
Four Main Types of Quantitative Research
1. Descriptive Research
Purpose: To describe the characteristics of a population or phenomenon being studied. It answers questions like "what," "who," "where," "when," and "how much." It does not attempt to explain why something occurs.
Characteristics:
- Focuses on describing the current state of a variable or phenomenon.
- Data is collected through surveys, observations, and other measurement tools.
- Results are often presented using measures of central tendency (mean, median, mode) and variability (standard deviation, range).
Examples:
- A survey determining the average number of hours students spend studying per week.
- A study measuring the percentage of people in a region who prefer a specific product.
- Analyzing census data to describe demographic characteristics of a city.
2. Correlational Research
Purpose: To determine the relationship or association between two or more variables. It explores whether variables change together and to what extent, but it does not establish cause and effect.
Characteristics:
- Examines the strength and direction of a relationship (positive, negative, or no correlation).
- Uses statistical methods like correlation coefficients (e.g., Pearson r).
- Variables are measured as they naturally occur, without manipulation.
Examples:
- Investigating the relationship between hours of sleep and test performance.
- Studying the correlation between income level and education level.
- Examining the association between exercise frequency and stress levels.
3. Causal-Comparative / Quasi-Experimental Research
Purpose: To investigate cause-and-effect relationships between variables when it's not possible or ethical to conduct a true experiment (e.g., the independent variable cannot be manipulated or participants cannot be randomly assigned to groups). This type attempts to establish cause-effect relationships among the variables.
Characteristics:
- Compares two or more groups that already exist based on a pre-existing condition or characteristic (the independent variable).
- The researcher does not manipulate the independent variable or randomly assign participants.
- Looks for differences in the dependent variable between the groups.
Examples:
- Comparing the academic performance of students who attended preschool versus those who did not.
- Investigating the impact of natural disasters on stress levels in affected versus unaffected communities.
- Studying the effects of different teaching methods on student outcomes in classrooms where methods were implemented prior to the study.
4. Experimental Research
Purpose: To establish a clear cause-and-effect relationship between variables. This is considered the most rigorous type of quantitative research for testing causal hypotheses. This type attempts to establish cause-effect relationships among the variables. These types of design are very similar to true experiments, but with some key differences, particularly regarding random assignment and manipulation of variables.
Characteristics:
- The researcher manipulates the independent variable.
- Participants are typically randomly assigned to different treatment groups (including a control group).
- Measures the effect of the manipulation on the dependent variable.
- Aims to control for extraneous variables to isolate the effect of the independent variable.
Examples:
- Testing the effectiveness of a new drug by giving it to one group and a placebo to another, randomly assigned group.
- Evaluating the impact of different types of marketing messages on consumer purchasing behavior by randomly assigning participants to view different messages.
- Comparing the learning outcomes of students taught using two different instructional techniques, with students randomly assigned to each technique.
Quantitative Research Types Overview
| Type | Primary Goal | Manipulation of Independent Variable | Random Assignment | Establishes Cause-Effect? |
|---|---|---|---|---|
| Descriptive | Describe characteristics | No | Not typically | No |
| Correlational | Identify relationships/associations | No | Not applicable | No (only correlation) |
| Causal-Comparative | Explore cause-effect in pre-existing groups | No (observes existing groups) | No | Tentative (due to lack of control) |
| Experimental | Establish clear cause-effect | Yes | Yes | Yes |
Understanding these different types helps researchers choose the appropriate design to answer their specific research questions and interpret the findings accurately.
