Statistics​
Interpreting Pearson's correlation coefficient

Statistics

Univariate statistics

• Measures of middle (mean, median mode)
• Measures of spread (range and interquartile range)
• Measures of spread (standard deviation)
• Histograms
• Box plots​

Bivariate statistics

• Association between variables
• The effect of outliers on correlation
• Causality
• Interpreting Pearson's correlation coefficient
• Interpolation and extrapolation​​

Previously we have described the strength of correlation by making visual observations of the data and subjectively deciding if the correlation is strong, moderate or weak. Since this observation is subjective and relies on the observers opinion, it is important to get a more precise measure of the strength of correlation between the variables. This can be achieved through a calculation known as Pearson's correlation coefficient.