Although the literal "answer" to the question is correlation
coefficient, the most useful practical answer for the real world of data
analysis is scatterplot before correlation coefficient. This is the
message to send. The scattergram conveys much more information. Owing to
pitfalls of outliers, non-linearity, subgroups it is best to look at the
data first. With widespread access to PC packages these days there is no
excuse. Like p-values versus confidence intervals, this debate belongs to
yesterday.
Rapid Response:
need to use graphics
I entirely agree with my statistical colleague.
Although the literal "answer" to the question is correlation
coefficient, the most useful practical answer for the real world of data
analysis is scatterplot before correlation coefficient. This is the
message to send. The scattergram conveys much more information. Owing to
pitfalls of outliers, non-linearity, subgroups it is best to look at the
data first. With widespread access to PC packages these days there is no
excuse. Like p-values versus confidence intervals, this debate belongs to
yesterday.
Competing interests:
None declared
Competing interests: No competing interests