McFilter

Lies, Damn Lies and Statistics

Last month the BBC website had a series of articles about the problems with the sorts of numbers and statistics oft bandied about by people and the media. They're well worth a read, even if it just means you'll never trust a number in a news report again...

• What the survey didn't say...
• The myth of counting
• Putting percentages in context
• Just what is average?

Tags: statistics bbc

OSM: Where's Your Nearest Postbox?

My project to help improve the OpenStreetMap has been continuing quite nicely, and I've run out of GPS traces of Rainford to do more mapping of the streets. So I've been looking at some of the other items I can add to the map - things like pubs, playing fields, and post boxes.

One of the things I've found tricky whilst getting to grips with editing the map is just what information I should add to each road or point-of-interest. I mean, there's quite a list - from obvious things like the street name or number through to whether or not it's streetlit or has a cycle path running alongside the road.

I thought it would help me, and also provide an easy introduction to adding detail to the map, if I wrote a few blog posts providing a template of the attributes that a certain common feature (road, pub, school, etc.) should have.

And what better thing to start with than the most simple item - a post box. Full details (including pictures!) after the jump...

Getting Started

First off, you'll need an account with OpenStreetMap. Sign up here if need be, then log in.

Next, find the location of the postbox you want to add on the map. If it turns out that someone else has already added all the postboxes near you, jump to the last step - you might still be able to help.

Click the "Edit" tab to switch to the Potlatch map editor. If this is the first time you're playing around with it, choose the "Play" option first and try things out before heading in to edit the live map data. Once you're happy with what you're doing you can just click the "Edit" tab again to reload Potlatch and let you choose the "Start" option.

Two handy tips for getting yourself out of trouble: If you start drawing accidentally, hitting the Esc key will cancel the line. And if you accidentally move something, Ctrl-Z will usually put things straight without you having to work out where it was originally.

Adding a Postbox

Double-click where you want to add the postbox. That'll give you a green dot surrounded by a yellow box to show that it's selected. You'll also see a little picture of a car with "(no preset)" written next to it appear just underneath the map.

Click on the car a few times until it switches round to the camera icon as pictured below.

Then choose the "post box" option from the preset name drop-down. You should have something that looks similar to this:

Finally, click somewhere else on the map to deselect the postbox and commit the changes. Your new addition will show up on the live map the next time the tiles get regenerated, which is generally within a week.

Extra Step for Bonus Credit

Once your postbox appears on the map, or if your nearest postbox is already on the map, there's one final piece of information you can add.

Head over to the Locating Postboxes project page and match your postbox to those from the Royal Mail's definitive list.

Tags: osm openstreetmap postbox tutorial

The BA Festival of Science 2008: Going Green With the Strawbridges

In Liverpool, Avoiding Being Eaten By a Spider

Well, we're finally here in Liverpool with Internet access and everything. It feels like an age since I left Torino, mainly because - err - it was over a month ago.

Things have been a bit hectic: first off finding somewhere to live (we've got a gorgeous apartment in the shadow of one of the cathedrals); then gathering all the possessions that we left scattered around the country when we headed off to Italy; sorting out utilities, phone, Internet; and finally buying a flat's-worth of furniture as the new place is unfurnished and all our existing furniture is being rented out to some nice people down in Cambridge still.

We managed most of the furniture buying in a day-long trawl of second-hand shops (the old church at the top of Upper Parliament Street is great) and charity shops around Liverpool and have some great buys. Lounge, dining room and bedroom fully furnished for £400. Result.

Most of the boxes have been unpacked now, and we've been venturing out exploring some of what the city has to offer. This weekend you couldn't miss the grand spectacle of La Princesse, a giant 50-ft steampunk spider.

We headed down on Saturday afternoon and fought our way through the crowds to Derby Square, where we were soaked to the skin with the water cannons fired over the crowd as part of the "water ballet". Luckily no-one seemed to mind, and many seemed to enjoy it. In between manufactured downpours, I took a few photos on my phone and have uploaded them to my flickr account. Start here if you'd like a look.

Tags: la_machine la_princesse liverpool