Interpreting outliers or clusters
We have described some information that may be read from a scatterplot. But how strong must the corrresponding patterns be before we should report them?
In both univariate and bivariate data sets, outliers or clusters must be distinct before we should conclude that they are real, in the absence of further external information confirming that the individuals are distinct.
Particularly in small data sets, outliers, clusters and other patterns may arise by chance, without being associated with any real features in the individuals.
Be careful not to overinterpret features in scatterplot unless they are well defined, especially if the sample size is small.