Gigabang for your buck

by Stubborn Mule on 1 May 2010 · 9 comments

This week Fairfax reported on Australia’s broadband pricing “war” in an article appearing in both the Sydney Morning Herald and the Age. The publisher thoughtfully spared online readers the egregious chart that it foisted on readers of the paper editions. Judging from this junk (to use the official adjective for low-quality charts), these newspapers should stick to journalism and steer clear of graphics.

The chart in question was brought to my attention by Mule Stable regular @zebra, who also kindly scanned it (and devised the headline of this post), allowing me to reproduce it here. It shows the pricing of a number of broadband internet plans offered by the four largest internet service providers (ISPs) in Australia.

Terribly designed chart showing prices vs download limits

Chart from print edition of The Age (29 April 2010)

It is a busy chart, made difficult to read by a number of ill-advised design decisions:

  • the horizontal axis reads from right to left rather than the conventional left to right
  • although labeled “Price vs Download”, price is on the horizontal axis, again violating convention*
  • repeating the ISP label for every point adds unnecessarily to the busy-ness of the chart and it also makes the legend redundant
  • labeling each point with the download limit (although not the price), adds more unnecessary ink

These conventions are arbitrary: we could just as well have developed a tradition in the West of reading from right to left, for example. But once a convention is in place, you have to have a very good reason to break with it. Otherwise, you end up making your chart harder for readers to interpret for no good reason.

But perhaps the biggest weakness in the chart is the labeling of the ISPs. Each has its own colour, but this is not enough for the eye to naturally group them together, which makes it hard to track the pricing trend provider by provider. This is easily addressed by connecting the points for each ISP with lines. Once this is done and the other short-comings are also addressed, a couple of anomalies in the data leap out immediately. Compared to their other plans, the Optus 100GB plan and the TPG 150GB appear dramatically over-priced, costing more than other plans that offer more data.

Improved chart of ISP plans $ v GBImproved version: Price vs Download limit

Of course, this phenomenon was there in the original chart, but it was hidden. So much so, that the journalist does not appear to have noticed at all as it went unremarked in the article. This is a good example of the power of good charting technique.

There are a number of possible explanations for the anomalous data points. They could simply be errors, although it is certainly not impossible (or perhaps even unlikely) that ISPs have illogical pricing policies. A more likely explanation is that the data includes apples and oranges: the higher-priced plans may be bundles offering additional services such as VOIP that are not included in the other more basic plans. Perhaps if Fairfax had done a better job on the chart in the first place, the journalist may have been prompted to answer this question for us.

* Typically “dependent variables” (the y of “y versus x”) appear on the vertical axis and “independent variables” on the horizontal axis.

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{ 9 comments… read them below or add one }

1 Ramanan May 2, 2010 at 12:06 am

:-)

2 Thomas May 2, 2010 at 6:26 am

-I just realized the article mentioned dowload limit which I confused with speed in my comment below-
Great Post! This reminds me of the challenging task of comparing cell phone plans.  It makes you pause to ponder if there is any usefulness in trying to compare broadband plans.  Here are a few observations this post made me think about (from a Canadian prospective):
1. Speed. All consumer broadband companies I know of make no guarantee whatsoever about claimed speed. One company’s definition of claimed speed may be different from another.
2. Speed (again). This is affected among by the type of connection. Cable is different from dsl which is different from fiber which is different from satellite. Cable for example is affected by the number of people connected in your area; dsl by the distance to the central office. 
3. Speed (again…). Broadband companies have devised clever ways to increase the perception of speed. Take my cable broadband provider, shaw. They have something called powerboost, a 20sec or so increase in speed whenever you start downloading something. How is that going go keep into account? Or shoul it even Be taken into account? 
4.Bundles. Just like you mention in the article. How do you even begin disentangling the difference in price due to bundles? 
One should get some real data, model the expected price/speed (real speed) and graph that with an informative confidence band. Or to make it more fun, graph the real/claimed speed!

3 Stubborn Mule May 2, 2010 at 8:49 am

Thomas: you are right that choosing plans is a hornet’s nest. If anything, it’s worse when it comes to mobile plans. Here in Australia, Telstra is consistently more expensive than the other provides, but when you sit in a cafe next to someone using Telstra with full data access and you have none with another provider, you start to wonder whether the extra is worth paying…

4 None May 2, 2010 at 4:57 pm

…or, is the real answer that Telstra vetted the chart and decided it would be better that it was seen first (at the left, as convention dictates)?

5 Ramanan May 3, 2010 at 10:50 pm
6 Thomas May 4, 2010 at 4:50 am

Indeed crazy graph. It seems that 1974 happens before 1973 (only after one realizes the x-axis is not time. Looks like one of those connect the dots to reveal the picture game… Strange coming from the NYT. Didn’t Tufte help them out years ago? I seem to recall there was something about the nyt in one of his books.

7 Stubborn Mule May 4, 2010 at 12:05 pm

I actually quite like it…while it is rather odd-looking it rewards closer study. I might even write a post about this one.

8 Ramanan May 4, 2010 at 12:18 pm

Yes cant find anything wrong about it – its just different.

9 Louise July 7, 2010 at 8:36 am

Sean – great blog!
I’ve been having a good laugh at many articles, including these crazy graphs. The newspaper version of the broadband price map is looks like an attempt to conceal the reality that Telstra doesn’t compete on price.

Well unravelled.

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