Viewing and testing correlations

One of the easiest ways to get a feel for your dataset is to examine the relationships of your variables with each other. While base R has the cor() function, the psych package has the lowerCor() function, which only displays the lower triangle of the correlation matrix for easier viewing and interpretation.

You can also use the corr.test() function to view several probability values, including p-values from t-tests of each correlation and confidence intervals for the correlations. P-values are corrected using the Holm correction by default.