Friday, September 02, 2011

Above average (or is it median?)

Samantha Riley and friends at the Quality Observatory at NHS South East Coast continue to publish the interesting and useful newsletter, Knowledge Matters. You can see the current issue here.  

This remains one of the best examples I have seen of a useful locally produced newsletter for hospital and health care staff of all backgrounds.  There is a variety of engaging pieces that have educational value for many.

This edition, for example, contains an article entitled "Ask an Analyst" that covers the difference between mean, median, and mode, concepts that are often confused, even by experienced folks.  I like how the presentation simply shows how the mean of a distribution can be skewed by outliers.  This is an important topic if you are measuring the quality of outcomes in a hospital.

Click on this excerpt below to enlarge it for an example of how that is presented:


e-Patient Dave said...

Best illustration I've ever seen, except I wish it were two different illustrations.

The median point is so important that the legendary Edward Tufte, of "visualizing quantitative information" fame, has a page on his site dedicated to Stephen Jay Gould's short-but-epic The Median Isn't The Message. Mandatory reading for anyone trying to cope with rough news (or trying to evaluate statistics for ANY reason, actually).

The screen grab of the excerpt is still too hard to read - are you able to copy & paste the text in?

Paul Levy said...

No, I tried.