Warn about interpreting correlations visually
Closed this issue · 2 comments
mpjashby commented
In some of their assessments, students have claimed 'strong relationships' or similar between variables based on a scatter plot, even when there is little or no actual relationship. Add a note to the section on scatter plots to warn students not to attempt to judge relationships visually.
mpjashby commented
This misunderstanding may be related to the text that teaches students to add a trend line to a scatter plot, since R will add a trend line regardless of the strength of any relationship. Maybe illustrate this by showing a matrix of scatterplots based on random data (with some variables skewed), showing the different trend lines produced.