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Anscombe’s quartet

As explained in Delivering Machine Learning Projects: From design to deployment

Anscombe’s Quartet is a set of four paired data sets with nearly identical summary statistics but substantially different distributions and relationships.

Anscombe’s quartet contains four paired data sets with different joint properties but identical-looking summary values: mean xₙ = 9, mean yₙ = 7.5, and Pearson correlation = 0.816. Plotting the data reveals relationships that summary statistics conceal. section 6.1.3

EDA checkpoint

Add a visualization ticket before modeling: plot the full data set, inspect how points relate, and compare the visible distributions with the reported summaries. section 6.1.3

Figure 6.1 Anscombe’s Quartet. Anscombe.svg: Schutz (label using subscripts): Avenue, CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0), via Wikimedia Commons

Use the quartet figure to compare four plots whose shared summaries obscure their different distributions and relationships. section 6.1.3

How Delivering Machine Learning Projects: From design to deployment covers it

How deep it goes
Defines the deceptive-statistics problem and motivates plotting, without developing a detailed statistical investigation of every data-set property.
Examples
Uses four paired data sets sharing means and Pearson correlation while displaying different joint distributions and relationships.
What it assumes
Assumes familiarity with summary statistics and correlation while reinforcing why visual exploratory analysis is necessary.
What you can do after
Evaluate/understand when plots expose structure that summary statistics hide before designing data sets for modeling.
How it connects
Connects summary statistics with exploratory data analysis, scatter plots, data visualization, and Pearson correlation.

Related concepts

This explainer was generated by Manning's knowledge graph from the text of Delivering Machine Learning Projects: From design to deployment. The section links point to the parts of the book it draws on.