Transformed scales are used in the epidemiology literature, of course, but
more often in the very technical literature. Indeed, I'm sure every
conceivable scale transformation has been used at some point. However,
epidemiology also serves wider, less mathematically inclined, public health
and medical audiences. Most health care practitioners wouldn't know what to
do with a log or square root scale. Also, epidemiological studies often end
up in the media. Can you see an epidemiologist trying to explain the square
root rate of influenza while on television? It is also very unlikely that
newspapers will print charts with log or square root scales. So, if we are
able to simply break the axis to make the scale more understandable to
non-statistically-oriented types, then we do (and should).
Lee
> -----Original Message-----
> From: Nick Cox [SMTP:[email protected]]
> Sent: Wednesday, May 14, 2003 6:15 PM
> To: [email protected]
> Subject: st: RE: RE: RE: broken axis symbol?
>
> Lee Sieswerda
>
> > One sees axis breaks in epidemiology, though not all that
> > often. For
> > example, one might be interested in graphing the weekly incidence of
> > influenza over several seasons. One may want to show that
> > Influenza B
> > strains were more common during the inter-epidemic periods,
> > while Influenza
> > A strains were more common during the epidemic periods. If
> > there were no
> > axis break, then the axis required to show the high
> > incidence rate during
> > the epidemic periods would make it difficult to see the
> > difference between
> > the A and B strains during the low-incidence inter-epidemic
> > periods. There
> > are other graphical solutions, to be sure, but the axis
> > break is a good
> > solution for this sort of thing. For clarity, it is
> > essential to break the
> > bar as well as the axis.
>
> Interesting, and I don't doubt that easy and effective comparison
> can be tricky.
>
> However, if the aim is comparison how far is that hindered
> as well as helped by the scale break?
>
> Does anyone in epidemiology use square root scales (given
> that zeros are perhaps common)?
>
> Nick
> [email protected]
>
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