I saw a link come across the front page of Hacker News today that blew my mind - not in a good way. In general, the content that appears on that page is pertinent and informative but the information in this link is just plain horse manure.
This post is basically a rant about everything I don't like about that infographic - leave now if your are otherwise aligned. You have been warned.
[Update: It seems that the graphic was updated to change petrabyte to petabye throughout. The remainder of the following artifacts, however, seem as they were originally presented]
Lets start with the term 'petrabyte'. You might think that there was a typo someplace on the page ('r' being next to 't' on the keyboard) and could understand seeing it once instead of petabyte. No, this infosludge is selling it as a measuring stick throughout. Unforgiven.
Now, lets start looking at the data contained in the display itself. One of the first data comparisons is the projected growth rainbows. Outside of what is being said in the text the shapes and values are lying. The 5% value is represented by 5 lines (1% per line) while the 40% value is represented with 12 lines (3.33% per line). If instead of the count of lines you consider the visual space of the arc you get an area of 39.27 (using radius 5). That should mean, if the aspect ratio is equal, that the area of the larger semi-circle should be 314.16 (8 times the smaller). Instead it is 226.19.
To the left of that there is a bubble containing the value of 235 terabytes. This represents the total data collected by the Library of Congress in the month of April in 2011. If this is an important benchmark or standard we should certainly be told at some point; along with how it relates to the other information it leads to. Instead, that value directs us to the Data Sectors. The problem is that values listed in the Data Sectors section are for yearly aggregates over entire sectors for 2009. Further problematic is the fact that the areas of the circles in the Data Sectors section do not correspond to the numbers listed under them. The ratio of the largest printed value and the smallest printed value is 18.94 while the ratio of the largest bubble to the smallest bubble is 25.0 (80px and 16px, respectively).
Moving through the chart to the next bubble lands us on a value of 3.8 [units elided]. What is the significance of this number - or the Securities and Investments sector it represents? What else in the chart references this value? Nothing that I can find; it's not even part of the five selected sections that follow it.
Then, again with the rainbow. This time 12 distinct rings is sufficient to represent two different values. Certainly there was effort in resizing those 12 rings for the smaller value - yet no one thought to use the correct scale? Boggles the mind.
Moving along in the Health sector we see that R&D is really important. It could reportedly capture $108 billion. That amount is $57 billion less than the Clinical area but R&D still gets a bigger bubble. I'll admit I'm compelled to agree with this choice - I totally dig R&D.
Personally, my favorite part of the entire chart is in the Retail sector. The caption is priceless: "The potential increase ... could be 60%." If I offered you a job and my pitch was "I might potentially pay you $60K", would you take it? Oh, you're probably likely to receive benefits, too.
Yay for consistency. As we are moving into Government not only have we temporarily switched to euros but we're also provided two different symbols to represent that change. Nothing like keeping your readers engaged by constantly changing the rules.
The last bubble I'll discuss is the "1 Petrabyte" centered near the bottom. How about one colossal waste of our time. Considering the discrepancies in the chart itself I'd be hesitant to trust the values as provided. The existence of delinquency like this is not altogether surprising; it's the fact that it is so popular that really appalls me.
NOTE: My discontent certainly does not represent my opinion of Hacker News and it's community. I simply find it unfortunate that so many are lead astray by these garish displays.
Showing posts with label responsibility. Show all posts
Showing posts with label responsibility. Show all posts
Tuesday, August 23, 2011
Thursday, May 26, 2011
Optical Disillusion
I dislike chartjunk. Not only is there a trend toward the incomprehensible but the movement comes with a ridiculous amount of flair. For all I can tell there exists a competition between infographic creators where the rules are based solely on who can cram more slop on a page.
Besides my obvious distaste for the style, there are sacrifices being made that compromise, or even forgo, the actual message - often without awareness or malice. Take, for example, the evolution of the pie chart.
For the sake of this example lets ignore the fact that a pie chart is a particularly poor way to display data to begin with. As a measure of two variables it provides a rough estimate of dominance but beyond that the human eye can not distinguish relative quantities across the various shapes. In almost all cases a simple bar chart provides a more precise description - even in the two variable case. A visual display of data should be able to stand on its own without the need of labels describing quantities or values. The pie chart fails in this respect, but I digress.
Consider a simple pie chart of two variables.
(As a measure of the strength of a pie chart as a communication tool, can you guess the values of the two areas? Go ahead, take a guess.)
The red portion of the chart is 55% and the blue portion is the remaining 45%. Without labels it is hard to distinguish exactly but serves to at least show the dominance of red over blue. The problem with trendy infographincs is that a simple pie chart is almost never sufficient in the layout. It needs exploding, or gradients, or even a third dimension.
Lets dress it up a bit and make a 3D pie chart with the same values.
So what's my beef about that? Lets consider the new representative areas of the chart. In the first chart, the values were inconspicuous but at least the color representation mapped directly to the underlying data.
Standard Pie Chart (red pixels) : 44295 (55.000%)
Standard Pie Chart (blue pixels): 36188 (44.900%)
In this new 'cooler' version of the chart we have skewed the data representation and thus our understanding of the overall message. In fact, by visible surface area alone we have changed the meaning of the chart entirely!
3D Pie Chart (red pixels) : 44792 (47.300%)
3D Pie Chart (blue pixels): 49740 (52.600%)
What is now required of us in this new chart, along with somehow mapping area to value, is to do accurate mathematical transformations in our heads to convert the 3D surface to an area in 2D. In fact, we need to now be able to deduce that roughly 52% of viewable surface area translates to 45% underlying data. The skew depends on the pitch, yaw, and roll so there is no magical formula here - every view will be a different mapping between surfaces.
I don't think people consider these details when compiling charts. In my estimate they are only trying to provide the most 'eye candy' for the intended consumer. The behavior is facilitated by common built-in chart generators (only 48 out of Excel's 288 pie chart variations are simple 2D charts) but there is no warning about the possible loss of meaning.
I'm certainly not among those pushing the envelope with infographics - this definitely makes my opinion biased. I keep things as simple as possible and for most data hungry crowds my approach is just too boring against current standards. I do believe there is a middle-ground, however; a place where rich graphics convey accurate data with minimal annotation markup. I only wish I knew how to bridge the gap.
A huge thanks to Dana Brown for taking the time to review and provide feedback on the first draft of this post.
Besides my obvious distaste for the style, there are sacrifices being made that compromise, or even forgo, the actual message - often without awareness or malice. Take, for example, the evolution of the pie chart.
For the sake of this example lets ignore the fact that a pie chart is a particularly poor way to display data to begin with. As a measure of two variables it provides a rough estimate of dominance but beyond that the human eye can not distinguish relative quantities across the various shapes. In almost all cases a simple bar chart provides a more precise description - even in the two variable case. A visual display of data should be able to stand on its own without the need of labels describing quantities or values. The pie chart fails in this respect, but I digress.
Consider a simple pie chart of two variables.
The red portion of the chart is 55% and the blue portion is the remaining 45%. Without labels it is hard to distinguish exactly but serves to at least show the dominance of red over blue. The problem with trendy infographincs is that a simple pie chart is almost never sufficient in the layout. It needs exploding, or gradients, or even a third dimension.
Lets dress it up a bit and make a 3D pie chart with the same values.
Standard Pie Chart (red pixels) : 44295 (55.000%)
Standard Pie Chart (blue pixels): 36188 (44.900%)
In this new 'cooler' version of the chart we have skewed the data representation and thus our understanding of the overall message. In fact, by visible surface area alone we have changed the meaning of the chart entirely!
3D Pie Chart (red pixels) : 44792 (47.300%)
3D Pie Chart (blue pixels): 49740 (52.600%)
What is now required of us in this new chart, along with somehow mapping area to value, is to do accurate mathematical transformations in our heads to convert the 3D surface to an area in 2D. In fact, we need to now be able to deduce that roughly 52% of viewable surface area translates to 45% underlying data. The skew depends on the pitch, yaw, and roll so there is no magical formula here - every view will be a different mapping between surfaces.
I don't think people consider these details when compiling charts. In my estimate they are only trying to provide the most 'eye candy' for the intended consumer. The behavior is facilitated by common built-in chart generators (only 48 out of Excel's 288 pie chart variations are simple 2D charts) but there is no warning about the possible loss of meaning.
I'm certainly not among those pushing the envelope with infographics - this definitely makes my opinion biased. I keep things as simple as possible and for most data hungry crowds my approach is just too boring against current standards. I do believe there is a middle-ground, however; a place where rich graphics convey accurate data with minimal annotation markup. I only wish I knew how to bridge the gap.
A huge thanks to Dana Brown for taking the time to review and provide feedback on the first draft of this post.
Thursday, March 31, 2011
The Price of Parking
I live in the Philadelphia area. If you've ever been to a Philadelphia sporting event you understand that there exists a certain kind of crazy that envelops the area just before game time and hangs around to varying degrees after the game depending on the outcome. If you are a true Philly fan you drink the crazy Kool-Aid. I don't, but my father-in-law has season tickets to the Flyers so occasionally I pretend to get a little punch drunk.
I don't live in an area that makes it feasible to take public transportation so I usually end up driving to the stadium from work. Parking is an assumed cost (as is $7 beers) but the last game I went to the price was pretty steep: $15. That is opposed to just three years earlier when I could get a spot for a mere $10. This was painful enough to force me to look at it more when I got home - and so I did.
There wasn't much to be gleaned from the fact that prices had risen over the past few years. Especially since Phildelphia built three new stadiums in the last ten years and, unfortunately, there is a blanket excuse to raise prices without cause lately: the poor economy. In either case, in thinking about all of this I started to consider how information can be used to manipulate people. More specifically, I imagined how the owner of the lot might try to explain away the increase to his (or her) customers.
As a consumer, I might approach the situation with the argument that the cost of parking has risen exponentially over the past five years. Certainly, from the following representation that might make sense:
Of course, that is presented in precisely the right way: the scale is only large enough to include the data points being shown; there is no history previous to 2007 where a consistent price may have been held (the two data points at $10 hint at this, however); and there is no comparison to other lots and/or prices in the area.
The counter to that point of view might look something like this:
Plenty going on here. First, and probably most important, is the scale: adjusting the scale results in a trend that appears closer to linear than exponential. Other factors: extending the range (going back to 2001); a carefully chosen cost of living number - modest, but keeps total profit negative; keeping the number of games high (it is a multiplier of the profit). In addition, the loss is not exactly negative income per patron, it is lost profit against the chosen cost of living increase.
In exploring this thought experiment I've only enforced what I already know: we, as presenters of data, have an obligation to be honest and straightforward. Data can be made to tell any convenient story; we would do well to remember that when consuming and producing information.
"The most dangerous untruths are truths moderately distorted." - Georg Lichtenberg
Incidentally, I had to leave that game early due to my daughter being very tired. On the way out I was helping my daughter put on her coat and a boy came over and asked if he could give her a puck. It seems he caught the puck during the game and wanted my daughter to have it. Well her eyes lit up and, of course, it completely made my night. Certainly worth the price of parking if you ask me.
I don't live in an area that makes it feasible to take public transportation so I usually end up driving to the stadium from work. Parking is an assumed cost (as is $7 beers) but the last game I went to the price was pretty steep: $15. That is opposed to just three years earlier when I could get a spot for a mere $10. This was painful enough to force me to look at it more when I got home - and so I did.
There wasn't much to be gleaned from the fact that prices had risen over the past few years. Especially since Phildelphia built three new stadiums in the last ten years and, unfortunately, there is a blanket excuse to raise prices without cause lately: the poor economy. In either case, in thinking about all of this I started to consider how information can be used to manipulate people. More specifically, I imagined how the owner of the lot might try to explain away the increase to his (or her) customers.
As a consumer, I might approach the situation with the argument that the cost of parking has risen exponentially over the past five years. Certainly, from the following representation that might make sense:
The counter to that point of view might look something like this:
In exploring this thought experiment I've only enforced what I already know: we, as presenters of data, have an obligation to be honest and straightforward. Data can be made to tell any convenient story; we would do well to remember that when consuming and producing information.
"The most dangerous untruths are truths moderately distorted." - Georg Lichtenberg
Incidentally, I had to leave that game early due to my daughter being very tired. On the way out I was helping my daughter put on her coat and a boy came over and asked if he could give her a puck. It seems he caught the puck during the game and wanted my daughter to have it. Well her eyes lit up and, of course, it completely made my night. Certainly worth the price of parking if you ask me.
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