Difference Between Descriptive and Inferential Statistics
Statistics is broadly divided into two main categories: Descriptive Statistics and Inferential Statistics. Both are used to analyze data, but their purpose and usage are different.
1. Descriptive Statistics
Meaning
Descriptive Statistics refers to organizing, summarizing, and presenting data in a meaningful way.
It describes the characteristics of the collected dataset without making any general conclusions beyond the data.
Purpose
To explain what the data shows.
Common Operations
- Calculating averages
- Creating frequency tables
- Generating graphs (e.g., histograms, bar charts, pie charts)
Common Tools
| Measure Type | Techniques |
|---|---|
| Central Tendency | Mean, Median, Mode |
| Variability | Range, Variance, Standard Deviation |
2. Inferential Statistics
Meaning
Inferential Statistics involves using data from a sample to make predictions or generalizations about a larger population.
Purpose
To draw conclusions, test hypotheses, and make decisions based on data.
Common Operations
- Hypothesis testing
- Confidence intervals
- Correlation & regression analysis
Goal
To infer characteristics of a population based on a sample.
✅ Example to Understand
Suppose a university has 10,000 students (population).
You collect the height of only 100 students (sample).
| Type | What You Do | What It Means |
|---|---|---|
| Descriptive Statistics | Calculate the average height of these 100 students | You are just describing the sample data. |
| Inferential Statistics | Use that sample’s average to estimate the average height of all 10,000 students | You are making a prediction about the full population. |
🟢 In Short
| Feature | Descriptive Statistics | Inferential Statistics |
|---|---|---|
| Purpose | Describe sample data | Make predictions about population |
| Based On | Only the observed data | Sample → Population |
| Techniques | Mean, Median, Mode, Graphs | Hypothesis Tests, Confidence Intervals, Regression |
| Output | Summary of data | Conclusion or Decision |
