Here’s the history of the Abortion data set
1) Jorge used some U.S. Census Bureau data (original Excel file) to visualize the abortion ratio as a small multiples chart,
2) In Small Multiples – Abortion Data 1980-2003, I have written about Jorge’s panel chart. I like the panel (small multiples) chart, but felt that it can be improved.
3) Jon Peltier posted on Re: Abortion Ratios 1980-2003 and Interactive Multiple Line Chart some nice Excel techniques to create interactive charts to analyze the Abortion data set.
Here is a different view on the data set as a Graphical Table using MicroCharts. The Graphical Table is a hybrid between the panel (small multiples) chart and a plain table of numbers. It nicely integrates the numbers with small charts, so-called sparklines, in a table. The sparklines show you the trend of the abortions over the years and the in-cell bar charts give you a feel for the distribution over the age groups:
This is a nice concise view of the data.
I’m sometimes concerned to see unscaled sparklines like these. In the panel charts, all of the panels showing the data in the first column of sparklines share a common scale. On this scale, the <15 curve is practically a flat line next to the bottom axis, while the 20-24 curve is far above, dropping from near the top to 1/3 of the way from the top to the bottom. In the sparklines above, unless I study the numbers on either side, the only difference between the two curves is that the 20-24 curve exhibits more waviness.
Certainly it’s difficult to show any resolution in just the height of a cell, in fact, that’s the point of a recent post by Stephen Few, in which he describes Panopticon’s new technique which uses a clever technique to greatly expand the effective scale of a cell’s height:
Time on the Horizon
There are always these trade-offs, aren’t there?
regarding the age group classifications in the table shown, if the last group is “40 and older” the first group should be “under 15” or “younger than 15,” not “less than 15” (as “less than” is not typically used to describe age).
unfortunately, your definition of abortion ratio still does not conform to that of demographers. and what is “abortion percentage”? also, in the “abortion percentage” section, why is there no trend line showing the change from 1980-2003?
from a demographer’s perspective, the chart would be much clearer if the three components were labeled “total abortions,” “percentage of abortions by age group,” and “my own made-up abortion ratio.”
Jon,
It’s true that sparklines have problems when you show data of the same measure across one or two dimensions in a graphical table. When you show them with a common scale most of them get a flat line.
I think it would make a lot of sense to add the correct usage of
sparklines and graphical table to the chart selection table,
http://blog.xlcubed.com/chart-rules-as-simple-as-possible-but-not-any-simpler/
…maybe with some input of you and Jorge.
The Horizon chart, certainly an interesting new approach, although I have to admit that I found it a bit confusing when I saw it the first time. I had to read Steve’s article to get it. I could imagine that many business users will have problems to understand the Horizon chart. Very much like the tree map, most business users like it initially, because it looks fancy, but in day to day business they use 99% of their time simple table and charts (well and MicroCharts of course :).
Andreas
Jenny,
The age group classifications, all the labels and naming is directly taken from the US Census Bureau web site
http://www.census.gov/compendia/statab/
nothing we invented.
We left out the “abortion percentage” trend line as it is identical to the abortion trend line.
Andreas
andreas – my mistake on the “less than 15” label.
you did invent the “abortion ratio” you’re using. the correct calculation (even per the data at BuCen that you linked to) is abortions per 1000 live births, not abortions per 1000 [abortions + live births].