on 13/8/02 5:46 PM, Marcello Pagano at [email protected] wrote:
> Ronan's points are well taken, and I agree with them.
> But to be fair to the histogram, both problems, of course,
> disappear to an extent if the histogram is defined with
> equiprobable bins--hist3 with the freqs equal.
I sometimes ask a class to look at a histogram while I count ten, then to
draw it roughly. It's interesting how many people cannot do it.
Interesting for two reasons
- drawing is an abstraction; we try to draw the important things and omit
those which are irrelevant. People find it difficult to distinguish between
relevant and irrelevant features of a histogram.
- comparing two histograms (or any two graphics) entails locating points of
difference. Again, because the reader cannot cone in on the important
points, they have no systematic way of comparing histograms.
Ronan M Conroy ([email protected])
Lecturer in Biostatistics
Royal College of Surgeons
Dublin 2, Ireland
+353 1 402 2431 (fax 2329)
--------------------
And now, Mr President, how about the global alliance against climate change?
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