---
title: "qq (quantile-quantile) plot"
description: "A qq plot from my Rblog post [Explore distributions with plots](https://www.psyctc.org/Rblog/posts/2023-11-18-explore-distributions-with-plots/) ![](https://www.psyctc.org/Rblog/posts/2023-11-18-explore-distributions-with-plots/explore-distributions-with-plots_files/figure-html5/qqplot3-1.png) These are diagnostic plots used to explore similarities between the distribution of values/scores in a sample against a theoretical distribution, typically the Gaussian distribution, or to compare distributions…"
url: "https://www.psyctc.org/psyctc/glossary2/qq-quantile-quantile-plot/"
updated: "2024-03-05"
category: All OM book glossary entries
---

# qq (quantile-quantile) plot

A qq plot from my Rblog post [Explore distributions with plots](https://www.psyctc.org/Rblog/posts/2023-11-18-explore-distributions-with-plots/)

![](https://www.psyctc.org/Rblog/posts/2023-11-18-explore-distributions-with-plots/explore-distributions-with-plots_files/figure-html5/qqplot3-1.png)

These are diagnostic plots used to explore similarities between the distribution of values/scores in a sample against a theoretical distribution, typically the Gaussian distribution, or to compare distributions of two distributions.

#### Details

Go to [Rblog](https://www.psyctc.org/Rblog/index.html) post [Explore distributions with plots](https://www.psyctc.org/Rblog/posts/2023-11-18-explore-distributions-with-plots/) for the explanation.

#### Try also

[Gaussian ("Normal") distribution](https://www.psyctc.org/psyctc/glossary2/gaussian-normal-distribution/)
[Kolmogorov-Smirnov test](https://www.psyctc.org/psyctc/glossary2/kolmogorov-smirnov-test/)
[Anderson-Darling test](https://www.psyctc.org/psyctc/glossary2/anderson-darling-test/)
[Cramer von Mises test](https://www.psyctc.org/psyctc/glossary2/cramer-von-mises-test/)
[Shapiro-Wilk test](https://www.psyctc.org/psyctc/glossary2/shapiro-wilk-test/)
[Shapiro-Francia test](https://www.psyctc.org/psyctc/glossary2/shapiro-francia-test/)
[Null hypothesis testing](https://www.psyctc.org/psyctc/glossary2/null-hypothesis-significance-testing-nhst-paradigm/)
[Distribution shape](https://www.psyctc.org/psyctc/glossary2/distribution-shape/)
[Null hypothesis significance testing (NHST) paradigm](https://www.psyctc.org/psyctc/glossary2/null-hypothesis-significance-testing-nhst-paradigm/)
[Sampling and sample frame](https://www.psyctc.org/psyctc/glossary2/dataset/)
[Population](https://www.psyctc.org/psyctc/glossary2/population/)

#### Chapters

Not in the book

#### Online resources

My [Rblog](https://www.psyctc.org/Rblog/index.html) post:
* [Explore distributions with plots](https://www.psyctc.org/Rblog/posts/2023-11-18-explore-distributions-with-plots/)
My [shiny apps](https://shiny.psyctc.org/):
* [App creating samples from Gaussian distribution](https://shiny.psyctc.org/apps/Gaussian1/) showing histogram, ecdf and qqplot

#### Dates

First created 19.xi.23