Question

When a correlation value is reported in research journals, there often is not an accompanying scatterplot. Explain why reported correlation values sho

Bivariate numerical data
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asked 2021-06-08
When a correlation value is reported in research journals, there often is not an accompanying scatterplot. Explain why reported correlation values should be supported with either a scatterplot or a description of the scatterplot.

Expert Answers (1)

2021-06-09
The correlation coefficient of two variables may be large even though these two variables aren’t even related. First we'd have to prove that these variables are related (using scatterplot, for instance), and then using the correlation coeflicient find "how much” they are related.
Another issue is that outlieracan significantly change the correlation coefficient (one can easily construct an example where only 1 outlier can change not, only the magnitude of the correlation coefiicient, but also its sign!). Therefore, the value of correlation coefficient is a very useful tool, but only if we are aslo provided with the scatterplot
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