What is the difference between qualitative and quantitative research methods?

Definition

Qualitative research methods focus on understanding concepts, experiences, or social phenomena through non-numerical data such as interviews, observations, and open-ended surveys. The goal is to explore meanings, patterns, and themes.

Quantitative research methods involve collecting and analyzing numerical data to identify patterns, test hypotheses, and make predictions. This approach uses statistical, mathematical, or computational techniques.

Worked Example

Suppose a researcher wants to study the impact of a new teaching method on student performance.

Qualitative Approach

• The researcher conducts interviews with students and teachers.
• Data: Students' opinions, feelings, and experiences.
• Analysis: Identifies themes such as "increased motivation" or "better understanding."

Quantitative Approach

• The researcher administers a standardized test before and after the new method.
• Data: Test scores (numerical).
• Analysis: Uses statistical tests, such as a paired $t$-test:

$$ t = \frac{\overline{X}_\text{after} - \overline{X}_\text{before}}{s / \sqrt{n}} $$

where:

• $\overline{X}_\text{after}$ = mean score after the method
• $\overline{X}_\text{before}$ = mean score before the method
• $s$ = standard deviation of the differences
• $n$ = number of students

If $t$ is statistically significant, the researcher concludes the method had an effect.

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Takeaways

• Qualitative research explores meanings and experiences; quantitative research measures and analyzes numerical data.
• Qualitative data is descriptive; quantitative data is statistical.
• Both methods can complement each other for a comprehensive understanding.