Author Archive for Waldo Jaquith

Page 124 of 549

On the Importance of Double-Checking Graphs

Published by Waldo Jaquith on February 23, 2009 in Meta News. 33 Comments

The Daily Progress has twice used extremely misleading charts in the past few weeks, and this seems like a good opportunity to highlight the importance of being a critical reader of charts and graphs. In both instance they employed bubble charts, a type of chart that is often avoided because people have an awfully hard time understanding them. At right is the chart that the paper employed on Sunday in Ranchana Dixit and Brandon Shulleeta’s “Can we afford our future?,” which tracked expensive capital improvement projects being planned in Charlottesville and Albemarle. As you can see, a minuscule amount is being spent on water and sewer improvements in comparison to Places29—in fact, more is being spent on Places29 than the other three combined. But the dollar values don’t add up. What’s going on?

The problem here is that people are really bad at comparing area. We do well with comparing colors, lengths, shapes, etc., but our brains are not well-equipped to figure out bubble charts. Doubly problematic is that this math behind the visuals in this chart is flat-out wrong. The area represented by the bottom bubble is $45.5M so, proportionally, the top bubble should represent $1,300M, not $312M. It’s 320% too big. Likewise, the middle two bubbles are significantly too large. The effect is to significantly exaggerate the disparity of the area’s spending priorities. Though having that big “$312 million” graphic above the fold on the front page of the paper is eye-catching, it’s misleading.

Here’s a side-by-side of the chart as it was presented in the Progress and how it should have looked:

As you can see, the effect isn’t nearly as striking. But it does have the benefit of being correct.

Stats-geek blog Junk Charts has a whole category to keep track of misleading bubble charts, because they’re so commonly misused. Understand, though, they’re not being misused maliciously by newspapers; they’re just easy to get wrong. In this case, the paper used an area-based chart with math that applies only to diameter leading to a geometric exaggeration of the data. The solution for the Progress is to use a simpler chart. (I’ve mocked it up as a bar chart, which is a much better format for this data.) This is certainly a minor sin, but it’s the sort of thing that (quite wrongly) leads readers to cry “bias!” when “mistake!” is a more appropriate response. And if you read this story in the paper yesterday, and didn’t think something was funny about that graph, the solution for you is to be a critical reader of charts and graphs. Look at the numbers, do a quick comparison and see if you’ve been given a false impression by the visuals.

Volunteer Farm to Help Stock Food Bank

Published by Waldo Jaquith on February 20, 2009 in Agriculture. Closed

The World Foundation for Children is setting up a volunteer-run farm in Culpeper County to provide meat and vegetables to the Charlottesville branch of the Blue Ridge Food Bank, Nate Delesline III writes in the Culpeper Star-Exponent. The organization has leased 100 acres for the next decade. They plan to start small, growing ten acres of potatoes, and move up from there. A couple of similar projects have been underway in the Shenandoah Valley for a while now, run by the same organization, reputedly with great success.

Efficiency Study Makes C’ville Recommendations

Published by Waldo Jaquith on February 18, 2009 in Government. 12 Comments

UVa’s Weldon Cooper Center has released the results of their efficiency study of the city government, Rachana Dixit writes in the Progress, and has recommended a series of ways that Charlottesville can save money without reducing the quality of government. One recommendation is to take another look at school funding, which has increased substantially per pupil in the past decade. Interestingly, the study found that Charlottesville’s staffing levels are pretty lean—save for the police and social services, which are at appropriate levels—which is the same conclusion drawn in the efficiency study of Albemarle, which was done by a totally different organization. It’s also recommended that some taxes and fees be increased slightly, including taking the personal property tax rate from 4.2% to 4.28%, which would match Albemarle’s rate.

You can read the study itself (2.5MB PDF) for the full details.

Furloughs at Area Businesses

Published by Waldo Jaquith on February 18, 2009 in Business and Meta News. 8 Comments

GE Fanuc and The Daily Progress are both furloughing employees to save money. The Progress reports on their own furloughs, writing that employees will have to take ten days off without pay in the coming months, with the paper’s offices closing on those days, but “the paper will continue to be produced and delivered each morning without interruption.” It’s tough to see how the staff is supposed to put out a decent paper the following day but, then, Media General’s cost-savings efforts have generally involved doing things that will make their product worse. GE Fanuc is furloughing their employees for two weeks, Brian McNeill writes in the Daily Progress, leaving 300 employees—half of their workforce—on unemployment for a couple of weeks. They will, however, continue to receive benefits.

There’s word of layoffs at LexisNexis, though unconfirmed, with an anonymous commenter (anonymous to you, not me) explaining that it’s of “temps”, though some of those temps have been working there for many years in the manner of full-time employees, so presumably LexisNexis doesn’t have to call them “layoffs.” The company has been gradually laying people off for months, rather than canning a bunch of people at the same time. That’s got to make it a grim place to work.

Bell Votes to Cut Funding for the Drug Court

Published by Waldo Jaquith on February 17, 2009 in Government, Law and Justice and Taxes. 37 Comments

In an effort to balance the state’s budget, Del. Rob Bell voted in favor of eliminating the funding for the Charlottesville/Albemarle Drug Court, Tasha Kates writes in the Daily Progress. Drug courts exist to help drug addicts kick the habit, rather than tossing them in prison, which is both ineffective and a lot more expensive. They’re a big money saver, which is why Sheriff Chip Harding (a Republican, like Del. Bell) is an ardent supporter of them. Since the budget amendment passed with 61% of the vote, this isn’t likely to change.

Cutting the funding for drug courts to save money reminds me of when Governor Mark Warner closed down the liquor stores one day a week to save money; since they’re profitable, that didn’t make much sense.

Sideblog