# What Type of Data Is Non-Parametric?

//

Angela Bailey

What Type of Data Is Non-Parametric?

Data analysis is a crucial part of any research or statistical study. When it comes to analyzing data, researchers often categorize it into different types based on their characteristics and properties.

One such classification is the distinction between parametric and non-parametric data. In this article, we will explore what non-parametric data is and how it differs from its counterpart.

## Parametric Data

Before diving into non-parametric data, let’s first understand what parametric data is. Parametric data refers to a type of data that follows a specific distribution, usually the normal distribution. This type of data has well-defined parameters, such as mean and standard deviation, which can be estimated accurately using statistical methods.

Examples of parametric data:

• Height measurements
• Weight measurements
• Test scores

## Non-Parametric Data

Non-parametric data, on the other hand, does not make any assumptions about the underlying distribution of the data. It does not require the estimation of specific parameters and instead focuses on ranking or ordering the observations.

Examples of non-parametric data:

• Ranks or orderings
• Categorical variables (e.g., gender)
• Ordinal scales (e., Likert scale ratings)

### Differences Between Parametric and Non-Parametric Data

The key difference between parametric and non-parametric data lies in their assumptions and analysis techniques.

Inferential Analysis:

• Parametric: Parametric data allows for more sophisticated statistical tests, such as t-tests and ANOVA, that rely on the assumptions of normality and homogeneity of variance.
• Non-Parametric: Non-parametric data requires different analysis techniques, such as the Mann-Whitney U test or the Kruskal-Wallis test, which do not assume a specific distribution.

Sample Size:

• Parametric: Parametric tests are generally more powerful when the sample size is large enough to meet the assumptions. They tend to perform better with normally distributed data.
• Non-Parametric: Non-parametric tests can be useful when the sample size is small or when the assumptions of parametric tests are violated.

### When to Use Non-Parametric Data Analysis?

The decision to use non-parametric data analysis depends on several factors:

• The type and distribution of your data: If your data does not meet the assumptions of parametric tests (e., non-normality), non-parametric tests may be more appropriate.
• The scale of measurement: Non-parametric tests are suitable for ordinal or categorical variables that cannot be treated as continuous.
• The research question: If your research question focuses on comparing medians or distributions rather than means, non-parametric tests may provide more meaningful insights.

## In Conclusion

In summary, non-parametric data encompasses variables that do not adhere to specific distributional assumptions. This type of data requires different analysis techniques that do not rely on normality or specific parameters. Understanding whether your data is parametric or non-parametric is crucial for selecting appropriate statistical methods and drawing accurate conclusions from your research.

Remember, when working with data, always consider the nature of your variables and the assumptions of different analysis techniques to ensure robust and reliable results.