Parametric vs Nonparametric Tests: Key Differences and Comparison

What type of test is used to compare observed and expected frequencies for a single categorical variable?

Which test is used to assess whether a new drug improves patients' symptoms when the data is paired?

What type of test is used to compare the median of two independent groups when the data is not normally distributed?

Which test is used to measure the association between ordinal or continuous variables?

When is it appropriate to use a non-parametric test?

What is the purpose of a parametric test?

Which characteristic of a test makes it suitable for comparing the median of two independent groups when the data is not normally distributed?

What is the primary reason why a non-parametric test is used instead of a parametric test?

Which type of test is used to compare the average test scores among three teaching methods?

What is the purpose of a goodness of fit test?

Which test is used to measure the association between two continuous variables?

What is the characteristic of a parametric test?

Which test is used to compare the median income across different job sectors?

What is the primary advantage of using a non-parametric test?

Which test is used to compare the exam scores of two groups, treatment and control, without assuming normality?

Parametric Tests

Assume specific distributions (usually normal) for data
Examples: Pearson Correlation, Linear Regression, Paired-samples T test, Independent Samples T test

Nonparametric Tests

Don't assume specific distributions (like the normal distribution) for data
Also known as distribution-free tests
Used when:
- Data isn't normally distributed
- Data is ordinal or categorical
- Assumptions for parametric tests aren't met
Examples: Mann-Whitney, Wilcoxon, Kruskal-Wallis, Spearman Correlation, Friedman's ANOVA, Jonchheeree-tespstra, Fisher exact test, Point biserial correlation

Goodness of Fit Test

Compares observed and expected frequencies for a single categorical variable
Example: A shop owner claims that an equal number of customers visit his shop each weekday, and records the weekly customer count
Uses Chi-squared test

Test Independence

Tests if two categorical variables are related
Examples: Mann-Whitney, Wilcoxon, Kruskal-Wallis, Spearman Correlation

Comparing Samples

Nonparametric tests can be used to compare differences between two independent samples when data isn't normally distributed
Examples: Compare exam scores of two groups (e.g., treatment vs. control) without assuming normality, compare median income across different job sectors

Measuring Association

Nonparametric tests can be used to measure association between ordinal or continuous variables
Examples: Spearman Correlation, Point biserial correlation

Understand the difference between parametric and nonparametric tests, including when to use each and the assumptions involved. Learn about goodness of fit tests and their applications.