I just want to know what they are for
--
QuietRanger

They are good to dunk in your coffee for breakfast.

Actually what they do is allow you to make a pie-type display, with multiple
series, so each concentric ring shows the variation in the amounts of the
categories being displayed.

However, pie charts are not particularly good at getting information into
people's heads. People aren't very good at comparing the angles, especially
if there are more than about four wedges in the pie. Because of this pie
charts should be avoided.

Donut charts are even worse, the rings have a bias due to having different
diameters and different surface areas. People's judgment of areas can be
even worse than that of angles, and the combination makes donuts something
to be avoided at all costs.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"QuietRanger" wrote in message
...
I just want to know what they are for
--
QuietRanger

QuietRanger

I have an example of 3 doughnut charts used to show proved oil reserves in
1984, 1994 and 2004. These charts are compared to a horizontal panel chart
of the same data.

http://processtrends.com/pg_charts_panel_dot_plot.htm

...Kelly

nospam e-mail address. Edit to reach me

kodayatprocesstrendsdotcom

"Jon Peltier" wrote in message
...
They are good to dunk in your coffee for breakfast.

Actually what they do is allow you to make a pie-type display, with
multiple series, so each concentric ring shows the variation in the
amounts of the categories being displayed.

However, pie charts are not particularly good at getting information into
people's heads. People aren't very good at comparing the angles,
especially if there are more than about four wedges in the pie. Because of
this pie charts should be avoided.

Donut charts are even worse, the rings have a bias due to having different
diameters and different surface areas. People's judgment of areas can be
even worse than that of angles, and the combination makes donuts something
to be avoided at all costs.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"QuietRanger" wrote in message
...
I just want to know what they are for
--
QuietRanger

"Just for the record", there is one apparently statistically sound use of
Excel's doughnuts -- see the article

Bordley, R.F., Representing trees using microsoft doughnut charts, The
American Statistician, 2002, vol. 56, no. 2, p. 139-147.

I just regret that the figures are rather sloppily drawn and that the macro
supposedly available for public download is nowhere to be found. (Anyone out
there able to provide it? I'd be really grateful.)

[Digression: As someone daily dealing with publishing in more or less "top"
scientific journala, I cannot help myself being left with a somewhat bitter
taste in the sense that it might very well have to do with the author being
a General Motors executive in addition to affiliated to two US universities,
while -- trust me from first-hand and second-hand experiance -- even such
generally trustworthy and impecaple journal as TAS exercises a whole lot
more severe technical and also content standards in other cases. But don't
get me wrong -- the article is OK and I like and support the idea.]

As for "getting information into people's heads", "people's judgment" and
the like, I would just like to add a note of caution as a semi-qualified
psychologist of perception (BSc & MSc) and statistician (PhD submitted). --
Sure, promoting Tufte's (which I fully and publicly and regularly do) and
Cleveland's teachings (erm, khm, problems with psychometric findings
commencing, though from the purely statistical point of view he undoubtedly
is another hero of data visualisation) is fine, but one should be aware of
the "human tendency" (I know, now I, a notorious Pompous European
Intellectual, am generalising and writing simplistic and <American stuff)
towards the "pendulum paradigm" of swinging from one extreme to the oposite
before finding the balance ...

In short, as with just about anything, there's much more to pies. And if you
(I) need a true hero from this (my) field, it should be Leland Wilkinson and
his Grammar of Graphics. (Just for the record, he wrote about <pies earlier
and it's even accessible from his website, but since there is a zillion of
other and wider issues to study here, the proverbial interested reader
should just start with the book).

Cordial regards,

Gaj Vidmar
Univ. of Ljubljana, Fac. of Medicine, Inst. of Biomedical Informatics
http://www.mf.uni-lj.si/ibmi-english [/biostat-center]
[- Research] & [- Software [- Excel]]

"Jon Peltier" wrote in message
...
They are good to dunk in your coffee for breakfast.

Actually what they do is allow you to make a pie-type display, with
multiple
series, so each concentric ring shows the variation in the amounts of the
categories being displayed.

However, pie charts are not particularly good at getting information into
people's heads. People aren't very good at comparing the angles,
especially
if there are more than about four wedges in the pie. Because of this pie
charts should be avoided.

Donut charts are even worse, the rings have a bias due to having different
diameters and different surface areas. People's judgment of areas can be
even worse than that of angles, and the combination makes donuts something
to be avoided at all costs.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"QuietRanger" wrote in message
...
I just want to know what they are for
--
QuietRanger

A concentric donut chart might be even worse, though either way the dot plot
approach is far superior.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"Kelly O'Day" wrote in message
...
QuietRanger

I have an example of 3 doughnut charts used to show proved oil reserves in
1984, 1994 and 2004. These charts are compared to a horizontal panel
chart of the same data.

http://processtrends.com/pg_charts_panel_dot_plot.htm

..Kelly

nospam e-mail address. Edit to reach me

kodayatprocesstrendsdotcom

"Jon Peltier" wrote in message
...
They are good to dunk in your coffee for breakfast.

Actually what they do is allow you to make a pie-type display, with
multiple series, so each concentric ring shows the variation in the
amounts of the categories being displayed.

However, pie charts are not particularly good at getting information into
people's heads. People aren't very good at comparing the angles,
especially if there are more than about four wedges in the pie. Because
of this pie charts should be avoided.

Donut charts are even worse, the rings have a bias due to having
different diameters and different surface areas. People's judgment of
areas can be even worse than that of angles, and the combination makes
donuts something to be avoided at all costs.

- Jon
-------
Jon Peltier, Microsoft Excel MVP
Tutorials and Custom Solutions
http://PeltierTech.com
_______


"QuietRanger" wrote in message
...
I just want to know what they are for
--
QuietRanger