What’s wrong with what3words?

Mapping service what3words can give your address to three metres’ accuracy using just three words. This sounds like a great idea—but, in practice, it’s more of a global.positioning.fail…

For anyone wondering, all of the what3words addresses used in the video are real, and shown in their actual positions. For example, you can find global.positioning.fail in North Dakota (as shown in the thumbnail if you look closely!) https://what3words.com/global.positio...

Video chapters

00:00 Introduction
01:47 The maths of what3words
03:28 1 - uses.confusing.language
04:30 2 - means.confusing.addresses
07:00 3 - offends.people.easily
10:23 4 - overlooks.vertical.positions
11:35 5 - ignores.earth.moves
12:50 6 - wording.translation.complex
13:55 7 - meanest.company.ever
15:36 make.maps.better


Sources and further reading

A useful general source of information on what3words is the OpenStreetMap Wiki entry on it https://wiki.openstreetmap.org/wiki/W...

For the accuracy in metres of a longitude/latitude measurement in degrees, see this wonderfully detailed answer https://gis.stackexchange.com/questio...

1 - uses.confusing.language
Vocabulary sizes: https://www.bbc.co.uk/news/world-4456...

2 - means.confusing.addresses
Andrew Tierney’s detailed blog reverse-engineering the what3words algorithm to expose why similar addresses appear near to one-another far more often than you’d expect at random https://cybergibbons.com/security-2/w...
Rescuers question what3words’ use in emergencies https://www.bbc.co.uk/news/technology...
https://what3words.com/employer.neatl... and https://what3words.com/employers.neat...

3 - offends.people.easily
This comment is a seemingly genuine complaint about the word ‘midgets’ being over someone’s home: https://shkspr.mobi/blog/2019/03/why-...

Using what3words for addresses
Chris Sheldrick’s TED Talk https://www.ted.com/talks/chris_sheld...
what3words blog on its use for addressing https://what3words.com/news/general/a...

4 - overlooks.vertical.positions
FAQ about how to deal with buildings with multiple floors https://support.what3words.com/en/art...

6 - ignores.earth.moves
Movement of different parts of Japan after the 2011 earthquake https://blogs.agu.org/mountainbeltway... https://www.gsi.go.jp/chibankansi/chi...
Australian Plate movement https://en.wikipedia.org/wiki/Austral...
Really interesting article on Australia’s grid update thanks to plate tectonics, and the UK’s own updated National Grid, known as OSGB36 https://www.ordnancesurvey.co.uk/news...
‘The current Number 10 started out life as Number 5, and was not renumbered until 1779.’ https://www.gov.uk/government/history...

7 - meanest.company.ever
What’s going on with WhatFreeWords? https://justpaste.it/39hat
Request to Twitter that it delete tweets referencing WhatFreeWords https://www.owenboswarva.com/misc/W3W...
Legal threat to security researcher Aaron Toponce in 2021: https://techcrunch.com/2021/04/30/wha...
Blog about just how intransparent what3words is https://blog.ldodds.com/2016/06/14/wh...
what3words accounts https://find-and-update.company-infor...

make.maps.better
Calculations behind my FourWordsFindWhere proposal https://docs.google.com/spreadsheets/...


Errata

At 12:09, anyway.nature.instance should be in Fukushima Prefecture, Japan, not near Brecon in Wales! (The earth didn’t move that far!)


Credits

Thanks so much to Huw James for filming this! Check out his tutorials for science filmmaking at https://www.sciencestorylab.co.uk

Thanks also to Tran Nguyen.


And finally…

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