Postcodes

From Freegle Wiki

Our system fundamentally works using postcodes. This explains why.

What's wrong with free-form locations?

Back in the days of Yahoo Groups, we had free-form locations that people typed themselves. That sounds appealing - so what's wrong with it? Several things, and a key point is that these problems happened over and over again, for a certain percentage of posts.

We got bad locations

  1. People didn't know what to put. Some entered vague terms like 'Anywhere', 'Edinburgh', 'Can collect', or 'just round the corner from the Post Office'. Users, especially new ones, can't be expected to know what kind of location a Freegle community needs - we should help them.
  2. So we did a lot of moderation around vague or wrong locations - bouncing posts back to users to correct them. That's off-putting for them, and tedious for us.
  3. They had to type locations. The more typing people have to do, the more friction there is, and the more people give up or make mistakes. Less typing is better.

Even those of us around in the Yahoo days tend to forget how much of a pain this was.

There are some solutions for getting human-readable, friendly locations, such as Google Autocomplete, but:

  • The good ones cost too much; the bad ones are too bad
  • They're aimed more at street or postal addresses than the kind of area locations we want
  • They don't include "unofficial" locations that everyone knows and uses but aren't on maps

Which community?

Another big problem in the Yahoo days was knowing which group to post on. We expected people to have found a group somehow, worked out from its name or a long description what area it covered, and decided where to post. That's a poor user experience, since it asks users - including new ones - to solve a geospatial puzzle in their heads. Imagine doing that if you're blind.

In some areas, especially densely populated ones, this problem was much worse than others. If you live somewhere it doesn't feel like a problem, your experience may not match areas where it is.

We spent a lot of time telling people they'd posted on the wrong group - frustrating for them, and a waste of our time. We shouldn't let people get into that situation in the first place.

More precise locations

For these reasons alone, it's very useful for the system to know a more precise location - there are other advantages too, covered below.

Many countries have long had similar issues with postal addresses, and introduced solutions such as postcodes or zip codes. These are now well-understood ways of defining a location precisely - roughly 92% of people know their own postcode from memory (see https://marcxsmith.medium.com/why-are-uk-postcodes-so-memorable-b0457e2e8a0d).

There's no international equivalent system:

  • Latitude/longitude isn't suitable for humans
  • "Find my location" buttons are often inaccurate
  • What3Words is trying to become a standard, but it's still rare for people in the UK to know their W3W address by heart

Our system asks for the postcode as the first thing when someone posts. This lets us identify a suitable default community for them - so they don't have to make a complex choice, and we don't have to spend time correcting wrong ones.

Friendly locations

We don't show people's full postcodes, for privacy - just the first part. It's still useful for many communities to have a human-readable location people would recognise, for example in an email; this is partly an accessibility matter too, since not everyone can view maps.

We map postcodes to friendly locations (see mapping postcodes) - broadly, we choose the smallest area the postcode is inside, or the closest area if it's not inside one. This means moderators effectively control which locations are in use on their community.

This mapping was set up many years ago - if you haven't looked at it recently, or at all, you should. If it looks a mess, sort it out yourself or get help. It can seem daunting, but you only have to sort it out once. Some communities make changes only when a complaint about a specific area arises.

Once the mapping is correct for your area, all postcodes map to sensible locations, and the problem of people getting locations wrong is removed.

Other benefits

Once we have a precise location, we can also:

  • Show people how far away a post is, to help them judge whether it's reachable
  • Find other nearby posts they might be particularly interested in
  • Automatically show people posts based on approximate travel time
  • Generate statistics on a postcode basis, which ties in with work councils and other organisations do (a lot of demographic data is postcode-based)

None of this is possible without locations accurate to around postcode level.

Missing postcodes?

We get our postcodes from Doogal. If a member's postcode isn't on their system, we won't get it. If a member says their postcode isn't recognised, email doogal@doogal.co.uk and ask about specific postcodes.

TrashNothing

TrashNothing has the same problems, but as an international system it can't have a single solution. So it does a mixture of things:

  • Lets you define the subject line format, e.g. to include a short location and part of a postcode
  • Lets you forbid certain locations
  • Tries to establish a precise location (via Find My Location and IP geolocation), relying on the user to notice and correct it if wrong

This still leaves a fair number of posts with a wrong location, which you'll occasionally see. You may need to ask TrashNothing users to correct their location:

To edit your post, follow the instructions at: https://help.trashnothing.com/how-do-i-edit-my-post. Once editing, click on the map to change where it shows, or use the 'New Location' option in the Location selection on the edit post page.

Link: ModTools