7 ms·

A Critical Analysis of the What3Words Geocoding Algorithm

168 points by ColinWright 3y ago

paulgb 3y ago
Interesting that the researchers didn’t analyze W3W directly because it would violate their ToS, but instead constructed their own word list. I would think that this sort of criticism of a technology used by the government (for emergency services) would be acceptable, similar to “fair use” in the US. Edit: it looks like the list itself is not even available, they would have had to reverse-engineer the app, so using a synthetic list makes more sense.
- regularfry 3y ago
  It's interesting because I'm fairly sure that work has already been done. Even without criticising the geocoding itself, the fact that there are singlular/plural pairs in the word list along with easily-confusable homophones says a lot about the product.
  - paulgb 3y ago
    It looks like a security researcher has looked into it and was threatened with legal action for releasing his source code. https://cybergibbons.com/security-2/why-what3words-is-not-suitable-for-safety-critical-applications/ https://cybergibbons.com/security-2/why-what3words-is-not-su... https://techcrunch.com/2021/04/30/what3words-legal-threat-whatfreewords/ https://techcrunch.com/2021/04/30/what3words-legal-threat-wh... Edit: initially I said “sued”, which was inaccurate. And the repo included the proprietary word list, not just code.
    - regularfry 3y ago
      Well, threatened with legal action and wasn't up for fighting it. It didn't get as far as him being sued, and while I can't blame him in the slightest for that choice, I would have been absolutely fascinated if it did go to court. A compatible reimplementation of something that's being sold to emergency services being slapped down because it's compatible sounds like the sort of thing useful precedent could have come out of.
    - jonatron 3y ago
      Your own previous comment doesn't match this take: https://news.ycombinator.com/item?id=21218385 https://news.ycombinator.com/item?id=21218385
      - paulgb 3y ago
        Ah, you got me! I didn’t realize from reading the TechCrunch article that the repo contained the actual word list, I stand by my original opinion that the takedown was legally valid.
        kryptiskt 3y ago
        Based on what law? You can't copyright mere facts like a list of words.
        growse 3y ago
        If creative effort was involved in curating that list, sure you can. A book is just a list of words.
        paulgb 3y ago
        You can't copyright the GPS coordinates of cities, because those are facts. The data would be the same whether you compiled it or not, and it would be absurd to grant someone a monopoly on that data. If you compile a word list yourself, you've created something that doesn't describe the factual state of the world; you've created something new. FWIW, before the debacle, even the (apparent) author of it appears to have admitted that it flaunted copyright: > FWIW, I have reverse-engineered the what3words address decoding algorithm. If anyone else with the luxury of flaunting patents and copyrights is curious, check out the demo at https://cardinalhood.github.io/what3words/ https://cardinalhood.github.io/what3words/. It’s written in JS, and runs in browsers and Node.js. https://blog.ldodds.com/2016/06/14/what-3-words-jog-on-mate/ https://blog.ldodds.com/2016/06/14/what-3-words-jog-on-mate/
        mjg59 3y ago
  - deleted 3y ago
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- PeterisP 3y ago
  It's worth noting that some huge limitations/risks of W3W are there because of the flaws in their word list choice, so if you're analyzing a different wordlist, you explicitly aren't looking at a big source of problems.
- NelsonMinar 3y ago
  There's a reverse engineering of What3Words from a few years ago floating around out there called "What Free Words". It includes what claims to be their word list. I imagine the researcher is familiar with this but has chosen not to include it in their research. (W3W is very aggressive about pursuing possibly spurious IP claims to remove any trace of What Free Words. In the past, even mentioning it in a comment like this is enough to attract a DMCA complaint.)
  - deleted 3y ago
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nateberkopec 3y ago
I volunteered in SAR for five years, and the topic of W3W would occasionally come up. For me, it’s just already damn hard to make sure you can hear numbers correctly over the radio. In marginal conditions, it’s a hell of a lot easier to use numbers (and requires less time due to not having to repeat or ask for clarification). Do I really want to be trying to say “arrows.midst.senses” over a handheld radio?
- switch007 3y ago
  SAR = Search and Rescue
- PeterisP 3y ago
  Especially since "arrows.midst.senses" and "arrow.midst.senses" are two different locations, and if you mishear it as "arrows.midst.sends", that's yet another different valid location. Really, there's all the research done (since the invention of early radio?) on what makes a phonetic alphabet or phonetic code usable in noisy conditions, and instead W3W effectively plants a field of rakes in front of blindfolded people.
  - margalabargala 3y ago
    Or worse, "arrows.midst.senses" and "arrows.mist.senses"
    - deleted 3y ago
      [deleted]
    - gorlilla 3y ago
      Arrows.missed.census
- permo-w 3y ago
  poor implementation aside, the format has its advantages over numerical coordinates besides the greater public awareness of w3w amongst certain demographics compared to coordinates, they may be harder to hear, but it's much easier to read out three words correctly than it is 16-18 numbers the thing with words is that they're easy to hear in context, but take them out of context and they're often indecipherable perhaps a system that gives each square a coherent-sounding sentence could be tried, although I'm sure that would have its difficulties too
Jabbles 3y ago
https://w3w.me.ss/ https://w3w.me.ss/ collects examples of bad experiences with W3W. It is linked in the paper.
- IshKebab 3y ago
  It really makes no sense to use it for emergency calls. 999/911 can already access your location by GPS. I think the issue is that other less emergency numbers can't (like 101). That's why they tell you to hang up and call 999 rather than transferring you. But I don't know why they just don't add more numbers to the "allowed to geolocate you" list. Or even build in a "send my location" button in phone calls. You wouldn't even need to modify the phone system - it could send DTFM tones.
  - matkoniecz 3y ago
    Note that GPS can be often unreliable or not precise enough. For example, it would be pretty useful to specify correct side of river/road/railway. Arriving at wrong side may result in needing to do very long detour.
    - dspillett 3y ago
      > Note that GPS can be often unreliable or not precise enough. But the W3W app identifies your position by GPS, meaning it is subject to the same general reliability problem via inheritance. Yes, it displays a map as well, so you can identify that you need to quote a different square, but in an emergency situation I'd posit that people are more likely to just read off the words and not really take in the displayed map. And the same solution works for GPS alone anyway – if you are reading your position using a phone app it is likely displaying an approximate map also.
      - matkoniecz 3y ago
        I am not claiming that 3 words is solving that problem, only that "forward GPS from phone" does not solve it. You will need reporter to describe location.
Recursing 3y ago
For more on this, and why I think we shouldn't advocate for W3W, see: https://shkspr.mobi/blog/2019/03/why-bother-with-what-three-words/ https://shkspr.mobi/blog/2019/03/why-bother-with-what-three-... for theoretical reasons and https://w3w.me.ss/ https://w3w.me.ss/ for some practical examples. https://plus.codes https://plus.codes seems much better, but sadly it uses random characters instead of words, which is much harder for humans to remember ( https://xkcd.com/936/ https://xkcd.com/936/ ), so I don't think it will ever catch on. That's pretty sad in my opinion, is the whole concept of using words to encode a location now owned by w3w? The implementation seems trivial
- ComodoHacker 3y ago
  >it uses random characters instead of words, which is much harder for humans to remember Do we really need to remember them, instead of just writing them down?
- lifthrasiir 3y ago
  > sadly it uses random characters instead of words It was explicitly designed in that way [1]. It does make harder to remember, but I think the memorizability constrains other goals too much. [1] https://github.com/google/open-location-code/wiki/Evaluation-of-Location-Encoding-Systems#desired-attributes https://github.com/google/open-location-code/wiki/Evaluation...
  - avidiax 3y ago
    This seems like a missing UX feature. Give the NATO (or regional) phonetic alphabet for the code, have a synthetic voice saying those characters, and maybe have an audio modem.
- Condition1952 3y ago
  What I dislike of plus.codes is that they have replaced GPS coordinates on google maps. GPS coordinates are multiplatform where only Google maps seems to be able to decode those fancy codes
  - 3y ago
rplnt 3y ago
The one single reason, no need to look any futher, for why it shouldn't be used by public services is because it's a private for profit operation. A simple concept that might have been useful, but is closed, so it won't be.
- mort96 3y ago
  And, to my understanding, the concept is patented, so nobody else can make an open version of it. So yes, the concept is kept from being useful through the power of the state. I really don't like patents.
  - DaiPlusPlus 3y ago
    IANAL - but (in most countries) you can’t patent a concept or an idea - only specific implementations of an idea (I.e. a physical invention) - software patents and business-process patents notwithstanding. But that doesn’t stop companies (especially those with a weak technical moat) from abusing the system.
    - mort96 3y ago
      "You can’t patent a concept or an idea" also doesn't prevent patent offices from granting patents on concepts and ideas. IMO, if we are to have patents at all, the patent offices should be robust, well-funded systems which make sure that no patent that's not genuinely a novel implementation of an idea gets granted. In reality, it seems like patent offices more or less accept anything that's written in dense enough lawyerese, and it's up to the legal system to slowly invalidate the bad patents after they've done a ton of harm. The fault here doesn't lie with the companies, but with the whole patent system where governments are way too quick to give out a state-backed monopoly of an idea. I find the whole practice despicable. Here's the What3Words patent: https://patents.google.com/patent/CA2909524A1/en https://patents.google.com/patent/CA2909524A1/en The first claim of the patent is: > 1. A computer implemented method of producing a location identifier comprising: > receiving at a processor geographical coordinates of a location; > at said processor performing the steps of: > converting the geographical coordinates into a single unique value n; > converting the single unique value n into a unique group of a plurality of > values; and converting the plurality of values into an equal plurality of > respective words; and making the plurality of words available as a location > identifier. It's hard to imagine anything remotely based around the idea to "convert a location to a set of words" which doesn't infringe on that claim.
mytailorisrich 3y ago
I don't really understand the need for W3W in most cases, at least in Europe. Can someone come up with something convincing?
- zaxomi 3y ago
  Money (for w3w) For everyone else: No.
- arlort 3y ago
  The most convincing use case (for plus codes, not w3w but same logic) I've seen is that it can be used instead of an address in slums and similar places where addresses aren't available/practical The problem is that it's useless without a phone but if you have access to a phone then a gps location is better, unless you have to remember it or put it in by hand
  - ElFitz 3y ago
    > unless you have to remember it or put it in by hand Or spell it out while in distress. But it seems w3w fits best in the "interesting but ultimately bad idea" bin.
  - MaxBarraclough 3y ago
    There's a counterpoint in another comment, [0] that it works poorly if you can't clearly hear each word. Plain old longitude and latitude numbers perform better in that regard. [0] https://news.ycombinator.com/item?id=37359790 https://news.ycombinator.com/item?id=37359790
- RowanH 3y ago
  I'm from NZ which has logical addressing. Trying to find some random business on some random shed, down some random lane in the middle of nowhere in the UK can be quite the challenge - post codes don't help and "turn left at the white post, go down the lane till you get to a crow that's staring south, then drive up past the.... " directions are terrible. What3Words has been great for finding those places that use it... easier than writing down a GPS co-ordinate.
realusername 3y ago
In French and (potentially other languages), I can add another criticism on top of the paper, some the words used in the dictionary are so obscure that a native speaker would not know them. They probably generated them randomly from a dictionary instead of asking native speakers. The whole project has then no real purpose if you have to spell unknown words.
- lifthrasiir 3y ago
  It also doesn't work well with agglutinative languages like Korean. The wordlist contains a lot of word sets only differentiated by postpositions (e.g. 기쁜 delightful vs. 기쁨 delight).
jokoon 3y ago
Generally, I would say standard addresses are better, because streets are already a form of information compression, since you always indicate a position on a street, you almost never indicate a position in the middle on a forest of a field. Streets are already transforming 2D information on a 1D line, a bit like a hilbert curve. GPS has a military use because the military go off-road, but citizens really don't (99.999% of the time). So yeah, it's another one of those case where software engineers are trying to solve a problem where there was no problem in the first place, because they don't like dealing with standard addresses. If you want to share a GPS coordinate, just use geohash, and use NATO alphabet if you need to share it orally.
- ElFitz 3y ago
  Adresses are anything but standard, many words can easily sound alike, and in some places that address couldn’t be properly spoken by a someone not familiar with the language. That’s when there even are adresses for your location. Many places simply don’t have one. As for gps coordinates, they are rather long and enunciating long sequences of characters can be quite tedious as anyone who has ever had to deal with game cd keys could tell. That, and most people don’t know NATO alphabet. So I’d, on the contrary, say a geohash-ish approache relying on a dictionary of carefully chosen hard to confuse and easy to enunciate words has its merits. But the optimal solution to me would be "press here to send your exact location".
- deleted 3y ago
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- Closi 3y ago
  > Generally, I would say standard addresses are better, because streets are already a form of information compression, since you always indicate a position on a street, you almost never indicate a position in the middle on a forest of a field. > GPS has a military use because the military go off-road, but citizens really don't (99.999% of the time) This is true for most of the world but not true for a lot of Africa - which does not have a real address system and relies on describing where a person lives and then doing a pin drop (websites will just accept pin drop).
intunderflow 3y ago
Publishing this from the UK is rather risky given What3Words have a tendency to engage in SLAPPs on anyone who pulls back the curtain on their product
- urschrei 3y ago
  No, it isn’t risky in the least. The analysis makes no use of proprietary data and illustrates potential problems which arise from choices made in the algorithm’s design in an abstract way, using a different word list from the claimed proprietary one that W3W use. The legal threat in question was made because W3W claimed that Andrew Toponce was linking to a product which used their allegedly proprietary word list in a series of tweets. Please don’t make unfounded fear-mongering comments about academic research – they cumulatively have the same effect as the threats you claim to be drawing attention to.
throwaway2562 3y ago
I’m pretty certain W3W are not now profitable and never will be. They’ve raised a ridiculous sum for a service which does not appear to be much-in demand.
- Nextgrid 3y ago
  The whole business was about trying to seek rent on the whole concept of addresses. I'm glad to see it not working out, though it would've been better if all the people involved had enough morals not to pursue such an idea in the first place.
  - ricktdotorg 3y ago
    in a different world, they might pivot to a wikimedia-like "open maps foundation", open-source everything while riding the wave of a huge amount of [new-to-them] good will, fat 501c3 donations and much smarter people than them helping fix their algorithm.
deleted 3y ago
[deleted]
solarkraft 3y ago
> What3Words has grown rapidly in popularity over the past few years and is used in logistical applications worldwide, including by emergency services It has? It is? I've known about it for many years and even seen billboards by them, yet never seen it used in practice.
- croes 3y ago
  Especially when you can easily send your exact GPS location if you make an emergency call with your smartphone.
  - matkoniecz 3y ago
    Note that GPS can be often unreliable or not precise enough. For example, it would be pretty useful to specify correct side of river/road/railway. Arriving at wrong side may result in needing to do very long detour.
    - dspillett 3y ago
      True, but no pure coordinate encoding system is going to help there. You need the user to be able to read a map of some sort to: 1. first verify that the position reading is accurate at all 2. adjust the reading appropriately 3. note any further navigation issues that could be important to people trying to head towards them (even with a 100% accurate position that could be a problem). The selling point of W3W is neither accuracy nor precision, but the claim that it reduces transcription errors that might send rescuers off in the wrong direction – for instance the difference between OSMAP references 680287 and 680278 putting you on the wrong side of the river with a few mile trip in either direction to get to the other side due to where crossing points are (there are no doubt better examples than this, I arbitrarily picked an example close by where I often run). This claim is disputed by a number of people some of whom make a good case (for instance https://www.bbc.co.uk/news/technology-56901363 https://www.bbc.co.uk/news/technology-56901363) and the fact that W3W has often chosen to respond to criticism with legal slaps instead of technical explanations suggests to me that the criticism is right.
    - 3y ago
fsh 3y ago
This is such a pointless product anyway. Every smartphone on the market can share its precise location in a machine-readable format with any other smartphone on the market. They even do it automatically when calling an emergency service. Why would you ever want to transmit a location by reading a string to someone?
- acc_297 3y ago
  If you are out of cell service and talking to search and rescue via a satellite phone This is the use case I’ve seen 3words applied most often
- 1970-01-01 3y ago
  >in a machine-readable format You're missing the point. The w3w coordinate system is designed to be readable by humans. The massive increasing adoption of this system should be a large hint that it is useful.
  - thelittlenag 3y ago
    Oddly enough W3W fails to go far enough in the direction of being friendly to humans. Hence all the many criticisms of it as a solution.
kmschaal 3y ago
I think What3Words is in principle a nice idea, but it could have been implemented much better. I am thinking of the following: - have a fixed pattern, e.g. adjective.adjective.noun. - create groups of words and put them in hierarchies. E.g. noun->animal->predator - cover the world with a one-dimensional Hilbert curve - Increment the noun along the curve. When all nouns are exhausted, start with the first noun again and increment the adjective in the middle, a.s.o. (analog to how incrementing a number with several digits works). With this approach, the location purple.flying.tiger would be next to purple.flying.lion.
- Gys 3y ago
  It is not like that by design. Remember, this is backed by VCs that already put in a lot of money and in some future will want to make a lot of money. The 3 words idea is patented and the basic idea is to have a drm protected database that is needed to find the actual location. The play the long game. Ultimately selling access to the database will make them money.
- hgomersall 3y ago
  That's specifically problematic: what was their location again? Uhm, it was purple flying something.. some kind of big cat.. lion or tiger.. Large conceptual distance between close physical locations is a feature not a bug.
- thelittlenag 3y ago
  You should check out https://www.qalocate.com/solutions/geohashphrase/ https://www.qalocate.com/solutions/geohashphrase/
- lhl 3y ago
  I spent a few minutes exploring a similar. Using the EFF wordlist (7776 words designed to be unambiguous)[1] you should be able to get down to about 100m^2 blocks (good enough for SAR), the BIP39 word list (2048) is a bit too resolution, but is a lot easier to pronounce, maybe worth some encoding shenanigans to get it to work). For my POC, I also used a simple 1D hilbert curve. Running a simulation and plotting the words, you actually get pretty decent resolution, and it's even alphabetical by distance. Output from simple demo w/ BIP39 (math might not be correct): https://ibb.co/MnmcRFk https://ibb.co/MnmcRFk but you can see that the word order actually make sense (although "winner" and "winter" are too phonetically similar, but still, gets the point across). [1] https://www.eff.org/deeplinks/2016/07/new-wordlists-random-passphrases https://www.eff.org/deeplinks/2016/07/new-wordlists-random-p...
karussell 3y ago
Is it really "geocoding" what they provide and is the 3 words code an "address equivalent"? Wikipedia says geocoding is: the process of taking a text-based description of a location, such as an address or the name of a place, and returning geographic coordinates, frequently latitude/longitude pair, to identify a location on the Earth's surface. In my opinion the 3 words are already geographic codes and not something like an address. It sounds like nit-pick but it shows the big problem of how they advertise that their service is a solution to vagueness of an address. Because if you have a phone with GPS available (or a similar device) you don't need "geocoding" because you already have the precise latitude/longitude pair. And if you do not have a device with GPS you'll also have a problem getting the 3 words.
- Waterluvian 3y ago
  Studied GIS for 8 years in university and I still cannot understand the use case for W3W. It removes information with little benefit. If you have a position using a CRS you’ve got lots of information about where it is relative to other positions in the same CRS. If you have a street address, you have hierarchical information of that location, and yea you can geocode it if you want to exchange topology for position. If you have a W3W you’ve got a memorable hash that tells you nothing at all until you geocode it. Making a W3W really feels like the opposite of geocoding. Or consider it like this: A coordinate pair tells you in some unit (degrees, metres, etc) where something is relative to other coordinates (or the datum). An address tells you where things are topologically: “it’s inside this city. Along this street. Beside these other addresses.” (Usually…) What does a W3W tell you? And let me guess… to get any information out of a W3W you must use their proprietary system. If that’s the case, what an absolutely moronic system to use.
  - 1970-01-01 3y ago
    >What does a W3W tell you? I'll bite. Using it as intended, both as a service and a physical coordinator (via 3 text chars), reveals a location with 3mx3m bounded precision. No other options exist that provide a solution to "where's the thing" without losing this key precision boundary.
mwexler 3y ago
I was surprised by the claims of the "ease" of sending your GPS coordinates. I had no idea how to do this before this post. I dug around a bit to see what I had missed. Some apps make this easier than others, with Google Maps still a mystery. In an emergency, or if I really needed a try location, I'd feel more comfortable with the dirt-simple nature of w3w then remembering how to find the lat/long and copying or saying all the digits (there are a lot of them!) Apple Maps surprised me by being the easiest. It shows lat/long under the "My Location" pane which appears when I tap the blue dot. They make it easy to copy /paste. Google Maps on iOS replaces that with a "Plus code". I can't find where my lat/long is in this thing, and gave up. (Hints and Spoilers welcome!) Over the years, I have tried other map apps which I pulled up to see how they handled lat/long: * Maps.me acts similarly to Apple Maps, tap the blue dot. * Here We Go maps makes you drop a pin at your location, but then displays lat/long. Magic Earth has same problem/approach. Who would remember how to do that in a rush? * Organic Maps over engineered this one: tap the blue arrow and lat/long appears, but when you tap it to copy, it changes to a new format each time (no commas, an alph-numeric I don't know, a url, a UTM, an MGRS, and then back to lat/long). Turns out you can press and hold to get a copy menu. * Google Earth displays the lat/long right on the screen... But it's not copyable. W3w may have implementation problems, but it does a great start on simplifying the answer to a verbal "where are you?". The rest of these, esp Google Maps, just aren't quite there yet.
- rozab 3y ago
  Google Maps pushes Plus Codes instead, they appear for every location: https://maps.google.com/pluscodes/ https://maps.google.com/pluscodes/ But normal co-ords also appear for me when I long tap anywhere
  - mwexler 3y ago
    Got it. You have to press and hold to get to the "non-Google" standard info. Thanks for the pointer!
  - verytrivial 3y ago
    It's a disappointing experience, isn't it? You can only get a raw lat/long if Maps can't generate an address. If it does, you're out of luck for lat/long -- it's gone from the UI as far as I can see.
twodave 3y ago
I feel like we could just boil this down to a math problem? Classic lat long uses, what? 10 decimal digits? Grouped into 2 sets of 5? Switching to base 26 can only really eliminate 1 digit from each set. That alone should make it pretty clear we aren’t going to make it much simpler. I suppose you could encode the whole thing as one set of 10 digits and maybe represent that as 7 alphanumeric characters, but now to share it over the phone you have to know a phonetic alphabet. Nah, let’s stick to numbers…
- joe__f 3y ago
  If you're working with three words I don't see why base 26 would be relevant, I think you'd be looking at n^3 where n is the size of the set of words that you're considering. So wouldn't you just, split the 2-sphere into N squares of a certain size, and then each square has (lat,long) associated with it, and then you pick n so that n^3 > N and come up with a mapping between your N (lat, long) points and your set of n^3 three word sentences?
  - twodave 3y ago
    I guess I wasn’t specifically trying to use 3 words but more just demonstrate that 10 decimal digits is about as simple as it gets in terms of clearly being able to communicate with that much precision over a low quality connection.
    - joe__f 3y ago
      It seems to me that you're demonstrating that What3Words doesn't provide precise coordinates on the globe to 3 decimal places. This is not surprising, given that they don't intend to do that, they chop the globe up into squares and provide less precision with easier human readability.
thelittlenag 3y ago
Yep. I was (and to some extent still am) part of a startup that found a better alternative to W3W. Our solution is the geohash phrase, which you can find a discussion of here: https://www.qalocate.com/solutions/geohashphrase/ https://www.qalocate.com/solutions/geohashphrase/ The only major thing W3W has going for it is a very, very good marketing department.
- NelsonMinar 3y ago
  Will there be a free, open source system for resolving a geohash phrase into a location? The #1 problem with What3Words is its proprietary rent-seeking business. Your link has ambiguous answers to "open source" and "free".
  - thelittlenag 3y ago
    The answer is yes, with the unfortunate qualifier that, for at least what we've put together, it won't be soon. The startup has been on pause for most of the last two years due to lack of traction. I don't have the time, money, or energy to devote to moving our current work, which is very rough and very much half-baked, into a useful state for motivated folks. That said, if someone else were to pick the idea up and move it forward on their own in the OSS space, then we'd (very likely) support that.
ofou 3y ago
Plus Codes are way better because they are open source. S2 is kind of analogous (also from Google), but 64-bit integers. I wonder if someone will ever come up with an Emoji encoding for GPS, regional flags might facilitate everything. It's just a random idea.
- ianburrell 3y ago
  I don't like how Plus Codes uses city names for relative ones. The result is longer than the full code. I also don't like how it uses the plus, it is hard to represent larger areas. I would have put the "+" at the beginning and use dots as separator, although I guess could look like phone number.
pseudotrash 3y ago
"Cybergibbons" from PentestPartners has done a teardown of W3W in 2021 on twitter. It was very spicy and the takeaway was not that it is just ugly implementation as some here suggest, but flawed by design: What3Words – The Algorithm https://cybergibbons.com/security-2/what3words-the-algorithm/ https://cybergibbons.com/security-2/what3words-the-algorithm... Why What3Words is not suitable for safety critical applications https://cybergibbons.com/security-2/why-what3words-is-not-suitable-for-safety-critical-applications/ https://cybergibbons.com/security-2/why-what3words-is-not-su...
- ShakataGaNai 3y ago
  I can understand overlooking homophones, but plurals was just stupid. Someone came up with a clever idea, and clearly they had some math/cipher skills. But w3w clearly had no linguists on staff. Even Wordle did a better job filtering their word list. Though with some of the words being so lengthy and linguistically complex, they would have been better moving to a four word system and assuring simpler words that was better filtered.
eternityforest 3y ago
Seems like a great opportunity for a new alternative system. Preferably with an error correcting code built in. Homophones shouldn't really matter, if you mess it up, the ECC could just fix it. Go with 4 words instead of 3. Take Diceware, treat the words as a base 7775 number, convert to binary, you get 50 bits. You could do some fancy reshuffling, reorder the words by similarity(Start with the first, then repeatedly pick the one with the smallest edit distance), and do the conversion to an integer such that any one word swapped to a close neighbor only produces a small change. My math knowledge is too limited to do this myself unless there's something to copy and paste or a brute force hack, but couldn't you do that by treating each word as a digit in 7775-ary gray code? Any one word being off to a nearby word, would then just give you an error in the low order bits of the latitude. Then you protect those bits with a hamming code, and have an overall 2 or 3 but checksum for everything, so at least some of the easy to make mistakes will be corrected, and most will probably be detected. Reliability could probably be better than reading off coordinates, still faster, with only one extra word. Plus the words themselves already have redundancy in them, if you make a typo, autocorrect can fix it, and if it gets the wrong one, the correction will likely catch it or flag the issue.
- gpt5 3y ago
  Good luck bypassing their patents.
- kybernetikos 3y ago
  I built a location to words system for fun a little while ago. https://Wherewords.id https://Wherewords.id I concluded something similar to you and went to 4 words. I spent the most time on the wordlist. I used the Google s2 library to split the world into a hierarchy of points. I even did an emoji checksum too although these days I'd probably do that differently. I really like the idea of an ECC actually, I might have a look at doing that, although it would remove the hierarchical nature that I like with the current system. Because it's hierarchical, people who know the context can skip initial words. Like two people in the 'decorate' region https://wherewords.id/decorate https://wherewords.id/decorate could just use the last three of the four words, or to indicate a number of locations near each other, you could just provide one location and then the other positions with just one or two words.
rudya 3y ago
Hi, I am the author of this article, it's interesting to see it being discussed here. A few points: It's definitely possible to reverse engineer the word list and other aspects of the w3w system. However I also want to make my anysis code public and I don't want to deal with w3w's lawyers. w3w make the basic claim that 1. similar addresses are far away from each other and 2. this makes mistakes obvious. 1 isn't true because they use a very naive randomization method. This was described before in an excellent blog post https://cybergibbons.com/security-2/what3words-the-algorithm/ https://cybergibbons.com/security-2/what3words-the-algorithm... I added some equations in my work. In the worst case you end up with a run of addresses like twice.over.x word.again.y repeat.phrase.z ... And maybe 10km away another run like twice.over.a word.again.b repeat.phrase.c ... Only one word is different, which obviously makes it much easier to confuse addresses. The other point is that around 25% of addresses (probably more) could be confused with 4 or more others. In that case, the AutoSuggest feature may not suggest the address you meant, and if it doesn't, there's not much you can do, since this is the only form of error correction available in w3w. w3w is quite popular here in the UK and I can see the appeal, it is more fun to shout out green.apple.regret than some alphanumeric string. But given the above problems (which i am sure w3w know about) that doesn't seem like a good enough reason to trust an app like this with matters of life and death.
heavenlyblue 3y ago
It's a very British startup that clearly has some connection to the government and is trying to lobby their way into NHS etc.

168 points by ColinWright 3y ago

Interesting that the researchers didn’t analyze W3W directly because it would violate their ToS, but instead constructed their own word list. I would think that this sort of criticism of a technology used by the government (for emergency services) would be acceptable, similar to “fair use” in the US. Edit: it looks like the list itself is not even available, they would have had to reverse-engineer the app, so using a synthetic list makes more sense.

regularfry 3y ago
It's interesting because I'm fairly sure that work has already been done. Even without criticising the geocoding itself, the fact that there are singlular/plural pairs in the word list along with easily-confusable homophones says a lot about the product.
- paulgb 3y ago
  It looks like a security researcher has looked into it and was threatened with legal action for releasing his source code. https://cybergibbons.com/security-2/why-what3words-is-not-suitable-for-safety-critical-applications/ https://cybergibbons.com/security-2/why-what3words-is-not-su... https://techcrunch.com/2021/04/30/what3words-legal-threat-whatfreewords/ https://techcrunch.com/2021/04/30/what3words-legal-threat-wh... Edit: initially I said “sued”, which was inaccurate. And the repo included the proprietary word list, not just code.
  - regularfry 3y ago
    Well, threatened with legal action and wasn't up for fighting it. It didn't get as far as him being sued, and while I can't blame him in the slightest for that choice, I would have been absolutely fascinated if it did go to court. A compatible reimplementation of something that's being sold to emergency services being slapped down because it's compatible sounds like the sort of thing useful precedent could have come out of.
  - jonatron 3y ago
    Your own previous comment doesn't match this take: https://news.ycombinator.com/item?id=21218385 https://news.ycombinator.com/item?id=21218385
    - paulgb 3y ago
      Ah, you got me! I didn’t realize from reading the TechCrunch article that the repo contained the actual word list, I stand by my original opinion that the takedown was legally valid.
      - kryptiskt 3y ago
        Based on what law? You can't copyright mere facts like a list of words.
        growse 3y ago
        If creative effort was involved in curating that list, sure you can. A book is just a list of words.
        paulgb 3y ago
        You can't copyright the GPS coordinates of cities, because those are facts. The data would be the same whether you compiled it or not, and it would be absurd to grant someone a monopoly on that data. If you compile a word list yourself, you've created something that doesn't describe the factual state of the world; you've created something new. FWIW, before the debacle, even the (apparent) author of it appears to have admitted that it flaunted copyright: > FWIW, I have reverse-engineered the what3words address decoding algorithm. If anyone else with the luxury of flaunting patents and copyrights is curious, check out the demo at https://cardinalhood.github.io/what3words/ https://cardinalhood.github.io/what3words/. It’s written in JS, and runs in browsers and Node.js. https://blog.ldodds.com/2016/06/14/what-3-words-jog-on-mate/ https://blog.ldodds.com/2016/06/14/what-3-words-jog-on-mate/
        mjg59 3y ago
- deleted 3y ago
  [deleted]
PeterisP 3y ago
It's worth noting that some huge limitations/risks of W3W are there because of the flaws in their word list choice, so if you're analyzing a different wordlist, you explicitly aren't looking at a big source of problems.
NelsonMinar 3y ago
There's a reverse engineering of What3Words from a few years ago floating around out there called "What Free Words". It includes what claims to be their word list. I imagine the researcher is familiar with this but has chosen not to include it in their research. (W3W is very aggressive about pursuing possibly spurious IP claims to remove any trace of What Free Words. In the past, even mentioning it in a comment like this is enough to attract a DMCA complaint.)
- deleted 3y ago
  [deleted]

nateberkopec 3y ago

I volunteered in SAR for five years, and the topic of W3W would occasionally come up. For me, it’s just already damn hard to make sure you can hear numbers correctly over the radio. In marginal conditions, it’s a hell of a lot easier to use numbers (and requires less time due to not having to repeat or ask for clarification). Do I really want to be trying to say “arrows.midst.senses” over a handheld radio?

switch007 3y ago
SAR = Search and Rescue
PeterisP 3y ago
Especially since "arrows.midst.senses" and "arrow.midst.senses" are two different locations, and if you mishear it as "arrows.midst.sends", that's yet another different valid location. Really, there's all the research done (since the invention of early radio?) on what makes a phonetic alphabet or phonetic code usable in noisy conditions, and instead W3W effectively plants a field of rakes in front of blindfolded people.
- margalabargala 3y ago
  Or worse, "arrows.midst.senses" and "arrows.mist.senses"
  - deleted 3y ago
    [deleted]
  - gorlilla 3y ago
    Arrows.missed.census
permo-w 3y ago
poor implementation aside, the format has its advantages over numerical coordinates besides the greater public awareness of w3w amongst certain demographics compared to coordinates, they may be harder to hear, but it's much easier to read out three words correctly than it is 16-18 numbers the thing with words is that they're easy to hear in context, but take them out of context and they're often indecipherable perhaps a system that gives each square a coherent-sounding sentence could be tried, although I'm sure that would have its difficulties too

Jabbles 3y ago

https://w3w.me.ss/ https://w3w.me.ss/ collects examples of bad experiences with W3W. It is linked in the paper.

IshKebab 3y ago
It really makes no sense to use it for emergency calls. 999/911 can already access your location by GPS. I think the issue is that other less emergency numbers can't (like 101). That's why they tell you to hang up and call 999 rather than transferring you. But I don't know why they just don't add more numbers to the "allowed to geolocate you" list. Or even build in a "send my location" button in phone calls. You wouldn't even need to modify the phone system - it could send DTFM tones.
- matkoniecz 3y ago
  Note that GPS can be often unreliable or not precise enough. For example, it would be pretty useful to specify correct side of river/road/railway. Arriving at wrong side may result in needing to do very long detour.
  - dspillett 3y ago
    > Note that GPS can be often unreliable or not precise enough. But the W3W app identifies your position by GPS, meaning it is subject to the same general reliability problem via inheritance. Yes, it displays a map as well, so you can identify that you need to quote a different square, but in an emergency situation I'd posit that people are more likely to just read off the words and not really take in the displayed map. And the same solution works for GPS alone anyway – if you are reading your position using a phone app it is likely displaying an approximate map also.
    - matkoniecz 3y ago
      I am not claiming that 3 words is solving that problem, only that "forward GPS from phone" does not solve it. You will need reporter to describe location.

Recursing 3y ago

For more on this, and why I think we shouldn't advocate for W3W, see: https://shkspr.mobi/blog/2019/03/why-bother-with-what-three-words/ https://shkspr.mobi/blog/2019/03/why-bother-with-what-three-... for theoretical reasons and https://w3w.me.ss/ https://w3w.me.ss/ for some practical examples. https://plus.codes https://plus.codes seems much better, but sadly it uses random characters instead of words, which is much harder for humans to remember ( https://xkcd.com/936/ https://xkcd.com/936/ ), so I don't think it will ever catch on. That's pretty sad in my opinion, is the whole concept of using words to encode a location now owned by w3w? The implementation seems trivial

ComodoHacker 3y ago
>it uses random characters instead of words, which is much harder for humans to remember Do we really need to remember them, instead of just writing them down?
lifthrasiir 3y ago
> sadly it uses random characters instead of words It was explicitly designed in that way [1]. It does make harder to remember, but I think the memorizability constrains other goals too much. [1] https://github.com/google/open-location-code/wiki/Evaluation-of-Location-Encoding-Systems#desired-attributes https://github.com/google/open-location-code/wiki/Evaluation...
- avidiax 3y ago
  This seems like a missing UX feature. Give the NATO (or regional) phonetic alphabet for the code, have a synthetic voice saying those characters, and maybe have an audio modem.
Condition1952 3y ago
What I dislike of plus.codes is that they have replaced GPS coordinates on google maps. GPS coordinates are multiplatform where only Google maps seems to be able to decode those fancy codes
- 3y ago

rplnt 3y ago

The one single reason, no need to look any futher, for why it shouldn't be used by public services is because it's a private for profit operation. A simple concept that might have been useful, but is closed, so it won't be.

mort96 3y ago
And, to my understanding, the concept is patented, so nobody else can make an open version of it. So yes, the concept is kept from being useful through the power of the state. I really don't like patents.
- DaiPlusPlus 3y ago
  IANAL - but (in most countries) you can’t patent a concept or an idea - only specific implementations of an idea (I.e. a physical invention) - software patents and business-process patents notwithstanding. But that doesn’t stop companies (especially those with a weak technical moat) from abusing the system.
  - mort96 3y ago
    "You can’t patent a concept or an idea" also doesn't prevent patent offices from granting patents on concepts and ideas. IMO, if we are to have patents at all, the patent offices should be robust, well-funded systems which make sure that no patent that's not genuinely a novel implementation of an idea gets granted. In reality, it seems like patent offices more or less accept anything that's written in dense enough lawyerese, and it's up to the legal system to slowly invalidate the bad patents after they've done a ton of harm. The fault here doesn't lie with the companies, but with the whole patent system where governments are way too quick to give out a state-backed monopoly of an idea. I find the whole practice despicable. Here's the What3Words patent: https://patents.google.com/patent/CA2909524A1/en https://patents.google.com/patent/CA2909524A1/en The first claim of the patent is: > 1. A computer implemented method of producing a location identifier comprising: > receiving at a processor geographical coordinates of a location; > at said processor performing the steps of: > converting the geographical coordinates into a single unique value n; > converting the single unique value n into a unique group of a plurality of > values; and converting the plurality of values into an equal plurality of > respective words; and making the plurality of words available as a location > identifier. It's hard to imagine anything remotely based around the idea to "convert a location to a set of words" which doesn't infringe on that claim.

mytailorisrich 3y ago

I don't really understand the need for W3W in most cases, at least in Europe. Can someone come up with something convincing?

zaxomi 3y ago
Money (for w3w) For everyone else: No.
arlort 3y ago
The most convincing use case (for plus codes, not w3w but same logic) I've seen is that it can be used instead of an address in slums and similar places where addresses aren't available/practical The problem is that it's useless without a phone but if you have access to a phone then a gps location is better, unless you have to remember it or put it in by hand
- ElFitz 3y ago
  > unless you have to remember it or put it in by hand Or spell it out while in distress. But it seems w3w fits best in the "interesting but ultimately bad idea" bin.
- MaxBarraclough 3y ago
  There's a counterpoint in another comment, [0] that it works poorly if you can't clearly hear each word. Plain old longitude and latitude numbers perform better in that regard. [0] https://news.ycombinator.com/item?id=37359790 https://news.ycombinator.com/item?id=37359790
RowanH 3y ago
I'm from NZ which has logical addressing. Trying to find some random business on some random shed, down some random lane in the middle of nowhere in the UK can be quite the challenge - post codes don't help and "turn left at the white post, go down the lane till you get to a crow that's staring south, then drive up past the.... " directions are terrible. What3Words has been great for finding those places that use it... easier than writing down a GPS co-ordinate.

realusername 3y ago

In French and (potentially other languages), I can add another criticism on top of the paper, some the words used in the dictionary are so obscure that a native speaker would not know them. They probably generated them randomly from a dictionary instead of asking native speakers. The whole project has then no real purpose if you have to spell unknown words.

lifthrasiir 3y ago
It also doesn't work well with agglutinative languages like Korean. The wordlist contains a lot of word sets only differentiated by postpositions (e.g. 기쁜 delightful vs. 기쁨 delight).

jokoon 3y ago

Generally, I would say standard addresses are better, because streets are already a form of information compression, since you always indicate a position on a street, you almost never indicate a position in the middle on a forest of a field. Streets are already transforming 2D information on a 1D line, a bit like a hilbert curve. GPS has a military use because the military go off-road, but citizens really don't (99.999% of the time). So yeah, it's another one of those case where software engineers are trying to solve a problem where there was no problem in the first place, because they don't like dealing with standard addresses. If you want to share a GPS coordinate, just use geohash, and use NATO alphabet if you need to share it orally.

ElFitz 3y ago
Adresses are anything but standard, many words can easily sound alike, and in some places that address couldn’t be properly spoken by a someone not familiar with the language. That’s when there even are adresses for your location. Many places simply don’t have one. As for gps coordinates, they are rather long and enunciating long sequences of characters can be quite tedious as anyone who has ever had to deal with game cd keys could tell. That, and most people don’t know NATO alphabet. So I’d, on the contrary, say a geohash-ish approache relying on a dictionary of carefully chosen hard to confuse and easy to enunciate words has its merits. But the optimal solution to me would be "press here to send your exact location".
deleted 3y ago
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Closi 3y ago
> Generally, I would say standard addresses are better, because streets are already a form of information compression, since you always indicate a position on a street, you almost never indicate a position in the middle on a forest of a field. > GPS has a military use because the military go off-road, but citizens really don't (99.999% of the time) This is true for most of the world but not true for a lot of Africa - which does not have a real address system and relies on describing where a person lives and then doing a pin drop (websites will just accept pin drop).

intunderflow 3y ago

Publishing this from the UK is rather risky given What3Words have a tendency to engage in SLAPPs on anyone who pulls back the curtain on their product

urschrei 3y ago
No, it isn’t risky in the least. The analysis makes no use of proprietary data and illustrates potential problems which arise from choices made in the algorithm’s design in an abstract way, using a different word list from the claimed proprietary one that W3W use. The legal threat in question was made because W3W claimed that Andrew Toponce was linking to a product which used their allegedly proprietary word list in a series of tweets. Please don’t make unfounded fear-mongering comments about academic research – they cumulatively have the same effect as the threats you claim to be drawing attention to.

throwaway2562 3y ago

I’m pretty certain W3W are not now profitable and never will be. They’ve raised a ridiculous sum for a service which does not appear to be much-in demand.

Nextgrid 3y ago
The whole business was about trying to seek rent on the whole concept of addresses. I'm glad to see it not working out, though it would've been better if all the people involved had enough morals not to pursue such an idea in the first place.
- ricktdotorg 3y ago
  in a different world, they might pivot to a wikimedia-like "open maps foundation", open-source everything while riding the wave of a huge amount of [new-to-them] good will, fat 501c3 donations and much smarter people than them helping fix their algorithm.

deleted 3y ago

[deleted]

solarkraft 3y ago

> What3Words has grown rapidly in popularity over the past few years and is used in logistical applications worldwide, including by emergency services It has? It is? I've known about it for many years and even seen billboards by them, yet never seen it used in practice.

croes 3y ago
Especially when you can easily send your exact GPS location if you make an emergency call with your smartphone.
- matkoniecz 3y ago
  Note that GPS can be often unreliable or not precise enough. For example, it would be pretty useful to specify correct side of river/road/railway. Arriving at wrong side may result in needing to do very long detour.
  - dspillett 3y ago
    True, but no pure coordinate encoding system is going to help there. You need the user to be able to read a map of some sort to: 1. first verify that the position reading is accurate at all 2. adjust the reading appropriately 3. note any further navigation issues that could be important to people trying to head towards them (even with a 100% accurate position that could be a problem). The selling point of W3W is neither accuracy nor precision, but the claim that it reduces transcription errors that might send rescuers off in the wrong direction – for instance the difference between OSMAP references 680287 and 680278 putting you on the wrong side of the river with a few mile trip in either direction to get to the other side due to where crossing points are (there are no doubt better examples than this, I arbitrarily picked an example close by where I often run). This claim is disputed by a number of people some of whom make a good case (for instance https://www.bbc.co.uk/news/technology-56901363 https://www.bbc.co.uk/news/technology-56901363) and the fact that W3W has often chosen to respond to criticism with legal slaps instead of technical explanations suggests to me that the criticism is right.
  - 3y ago

fsh 3y ago

This is such a pointless product anyway. Every smartphone on the market can share its precise location in a machine-readable format with any other smartphone on the market. They even do it automatically when calling an emergency service. Why would you ever want to transmit a location by reading a string to someone?

acc_297 3y ago
If you are out of cell service and talking to search and rescue via a satellite phone This is the use case I’ve seen 3words applied most often
1970-01-01 3y ago
>in a machine-readable format You're missing the point. The w3w coordinate system is designed to be readable by humans. The massive increasing adoption of this system should be a large hint that it is useful.
- thelittlenag 3y ago
  Oddly enough W3W fails to go far enough in the direction of being friendly to humans. Hence all the many criticisms of it as a solution.

kmschaal 3y ago

I think What3Words is in principle a nice idea, but it could have been implemented much better. I am thinking of the following: - have a fixed pattern, e.g. adjective.adjective.noun. - create groups of words and put them in hierarchies. E.g. noun->animal->predator - cover the world with a one-dimensional Hilbert curve - Increment the noun along the curve. When all nouns are exhausted, start with the first noun again and increment the adjective in the middle, a.s.o. (analog to how incrementing a number with several digits works). With this approach, the location purple.flying.tiger would be next to purple.flying.lion.

Gys 3y ago
It is not like that by design. Remember, this is backed by VCs that already put in a lot of money and in some future will want to make a lot of money. The 3 words idea is patented and the basic idea is to have a drm protected database that is needed to find the actual location. The play the long game. Ultimately selling access to the database will make them money.
hgomersall 3y ago
That's specifically problematic: what was their location again? Uhm, it was purple flying something.. some kind of big cat.. lion or tiger.. Large conceptual distance between close physical locations is a feature not a bug.
thelittlenag 3y ago
You should check out https://www.qalocate.com/solutions/geohashphrase/ https://www.qalocate.com/solutions/geohashphrase/
lhl 3y ago
I spent a few minutes exploring a similar. Using the EFF wordlist (7776 words designed to be unambiguous)[1] you should be able to get down to about 100m^2 blocks (good enough for SAR), the BIP39 word list (2048) is a bit too resolution, but is a lot easier to pronounce, maybe worth some encoding shenanigans to get it to work). For my POC, I also used a simple 1D hilbert curve. Running a simulation and plotting the words, you actually get pretty decent resolution, and it's even alphabetical by distance. Output from simple demo w/ BIP39 (math might not be correct): https://ibb.co/MnmcRFk https://ibb.co/MnmcRFk but you can see that the word order actually make sense (although "winner" and "winter" are too phonetically similar, but still, gets the point across). [1] https://www.eff.org/deeplinks/2016/07/new-wordlists-random-passphrases https://www.eff.org/deeplinks/2016/07/new-wordlists-random-p...

karussell 3y ago

Is it really "geocoding" what they provide and is the 3 words code an "address equivalent"? Wikipedia says geocoding is: the process of taking a text-based description of a location, such as an address or the name of a place, and returning geographic coordinates, frequently latitude/longitude pair, to identify a location on the Earth's surface. In my opinion the 3 words are already geographic codes and not something like an address. It sounds like nit-pick but it shows the big problem of how they advertise that their service is a solution to vagueness of an address. Because if you have a phone with GPS available (or a similar device) you don't need "geocoding" because you already have the precise latitude/longitude pair. And if you do not have a device with GPS you'll also have a problem getting the 3 words.

Waterluvian 3y ago
Studied GIS for 8 years in university and I still cannot understand the use case for W3W. It removes information with little benefit. If you have a position using a CRS you’ve got lots of information about where it is relative to other positions in the same CRS. If you have a street address, you have hierarchical information of that location, and yea you can geocode it if you want to exchange topology for position. If you have a W3W you’ve got a memorable hash that tells you nothing at all until you geocode it. Making a W3W really feels like the opposite of geocoding. Or consider it like this: A coordinate pair tells you in some unit (degrees, metres, etc) where something is relative to other coordinates (or the datum). An address tells you where things are topologically: “it’s inside this city. Along this street. Beside these other addresses.” (Usually…) What does a W3W tell you? And let me guess… to get any information out of a W3W you must use their proprietary system. If that’s the case, what an absolutely moronic system to use.
- 1970-01-01 3y ago
  >What does a W3W tell you? I'll bite. Using it as intended, both as a service and a physical coordinator (via 3 text chars), reveals a location with 3mx3m bounded precision. No other options exist that provide a solution to "where's the thing" without losing this key precision boundary.

mwexler 3y ago

I was surprised by the claims of the "ease" of sending your GPS coordinates. I had no idea how to do this before this post. I dug around a bit to see what I had missed. Some apps make this easier than others, with Google Maps still a mystery. In an emergency, or if I really needed a try location, I'd feel more comfortable with the dirt-simple nature of w3w then remembering how to find the lat/long and copying or saying all the digits (there are a lot of them!) Apple Maps surprised me by being the easiest. It shows lat/long under the "My Location" pane which appears when I tap the blue dot. They make it easy to copy /paste. Google Maps on iOS replaces that with a "Plus code". I can't find where my lat/long is in this thing, and gave up. (Hints and Spoilers welcome!) Over the years, I have tried other map apps which I pulled up to see how they handled lat/long: * Maps.me acts similarly to Apple Maps, tap the blue dot. * Here We Go maps makes you drop a pin at your location, but then displays lat/long. Magic Earth has same problem/approach. Who would remember how to do that in a rush? * Organic Maps over engineered this one: tap the blue arrow and lat/long appears, but when you tap it to copy, it changes to a new format each time (no commas, an alph-numeric I don't know, a url, a UTM, an MGRS, and then back to lat/long). Turns out you can press and hold to get a copy menu. * Google Earth displays the lat/long right on the screen... But it's not copyable. W3w may have implementation problems, but it does a great start on simplifying the answer to a verbal "where are you?". The rest of these, esp Google Maps, just aren't quite there yet.

rozab 3y ago
Google Maps pushes Plus Codes instead, they appear for every location: https://maps.google.com/pluscodes/ https://maps.google.com/pluscodes/ But normal co-ords also appear for me when I long tap anywhere
- mwexler 3y ago
  Got it. You have to press and hold to get to the "non-Google" standard info. Thanks for the pointer!
- verytrivial 3y ago
  It's a disappointing experience, isn't it? You can only get a raw lat/long if Maps can't generate an address. If it does, you're out of luck for lat/long -- it's gone from the UI as far as I can see.

twodave 3y ago

I feel like we could just boil this down to a math problem? Classic lat long uses, what? 10 decimal digits? Grouped into 2 sets of 5? Switching to base 26 can only really eliminate 1 digit from each set. That alone should make it pretty clear we aren’t going to make it much simpler. I suppose you could encode the whole thing as one set of 10 digits and maybe represent that as 7 alphanumeric characters, but now to share it over the phone you have to know a phonetic alphabet. Nah, let’s stick to numbers…

joe__f 3y ago
If you're working with three words I don't see why base 26 would be relevant, I think you'd be looking at n^3 where n is the size of the set of words that you're considering. So wouldn't you just, split the 2-sphere into N squares of a certain size, and then each square has (lat,long) associated with it, and then you pick n so that n^3 > N and come up with a mapping between your N (lat, long) points and your set of n^3 three word sentences?
- twodave 3y ago
  I guess I wasn’t specifically trying to use 3 words but more just demonstrate that 10 decimal digits is about as simple as it gets in terms of clearly being able to communicate with that much precision over a low quality connection.
  - joe__f 3y ago
    It seems to me that you're demonstrating that What3Words doesn't provide precise coordinates on the globe to 3 decimal places. This is not surprising, given that they don't intend to do that, they chop the globe up into squares and provide less precision with easier human readability.

thelittlenag 3y ago

Yep. I was (and to some extent still am) part of a startup that found a better alternative to W3W. Our solution is the geohash phrase, which you can find a discussion of here: https://www.qalocate.com/solutions/geohashphrase/ https://www.qalocate.com/solutions/geohashphrase/ The only major thing W3W has going for it is a very, very good marketing department.

NelsonMinar 3y ago
Will there be a free, open source system for resolving a geohash phrase into a location? The #1 problem with What3Words is its proprietary rent-seeking business. Your link has ambiguous answers to "open source" and "free".
- thelittlenag 3y ago
  The answer is yes, with the unfortunate qualifier that, for at least what we've put together, it won't be soon. The startup has been on pause for most of the last two years due to lack of traction. I don't have the time, money, or energy to devote to moving our current work, which is very rough and very much half-baked, into a useful state for motivated folks. That said, if someone else were to pick the idea up and move it forward on their own in the OSS space, then we'd (very likely) support that.

ofou 3y ago

Plus Codes are way better because they are open source. S2 is kind of analogous (also from Google), but 64-bit integers. I wonder if someone will ever come up with an Emoji encoding for GPS, regional flags might facilitate everything. It's just a random idea.

ianburrell 3y ago
I don't like how Plus Codes uses city names for relative ones. The result is longer than the full code. I also don't like how it uses the plus, it is hard to represent larger areas. I would have put the "+" at the beginning and use dots as separator, although I guess could look like phone number.

pseudotrash 3y ago

"Cybergibbons" from PentestPartners has done a teardown of W3W in 2021 on twitter. It was very spicy and the takeaway was not that it is just ugly implementation as some here suggest, but flawed by design: What3Words – The Algorithm https://cybergibbons.com/security-2/what3words-the-algorithm/ https://cybergibbons.com/security-2/what3words-the-algorithm... Why What3Words is not suitable for safety critical applications https://cybergibbons.com/security-2/why-what3words-is-not-suitable-for-safety-critical-applications/ https://cybergibbons.com/security-2/why-what3words-is-not-su...

ShakataGaNai 3y ago
I can understand overlooking homophones, but plurals was just stupid. Someone came up with a clever idea, and clearly they had some math/cipher skills. But w3w clearly had no linguists on staff. Even Wordle did a better job filtering their word list. Though with some of the words being so lengthy and linguistically complex, they would have been better moving to a four word system and assuring simpler words that was better filtered.

eternityforest 3y ago

Seems like a great opportunity for a new alternative system. Preferably with an error correcting code built in. Homophones shouldn't really matter, if you mess it up, the ECC could just fix it. Go with 4 words instead of 3. Take Diceware, treat the words as a base 7775 number, convert to binary, you get 50 bits. You could do some fancy reshuffling, reorder the words by similarity(Start with the first, then repeatedly pick the one with the smallest edit distance), and do the conversion to an integer such that any one word swapped to a close neighbor only produces a small change. My math knowledge is too limited to do this myself unless there's something to copy and paste or a brute force hack, but couldn't you do that by treating each word as a digit in 7775-ary gray code? Any one word being off to a nearby word, would then just give you an error in the low order bits of the latitude. Then you protect those bits with a hamming code, and have an overall 2 or 3 but checksum for everything, so at least some of the easy to make mistakes will be corrected, and most will probably be detected. Reliability could probably be better than reading off coordinates, still faster, with only one extra word. Plus the words themselves already have redundancy in them, if you make a typo, autocorrect can fix it, and if it gets the wrong one, the correction will likely catch it or flag the issue.

gpt5 3y ago
Good luck bypassing their patents.
kybernetikos 3y ago
I built a location to words system for fun a little while ago. https://Wherewords.id https://Wherewords.id I concluded something similar to you and went to 4 words. I spent the most time on the wordlist. I used the Google s2 library to split the world into a hierarchy of points. I even did an emoji checksum too although these days I'd probably do that differently. I really like the idea of an ECC actually, I might have a look at doing that, although it would remove the hierarchical nature that I like with the current system. Because it's hierarchical, people who know the context can skip initial words. Like two people in the 'decorate' region https://wherewords.id/decorate https://wherewords.id/decorate could just use the last three of the four words, or to indicate a number of locations near each other, you could just provide one location and then the other positions with just one or two words.

rudya 3y ago

Hi, I am the author of this article, it's interesting to see it being discussed here. A few points: It's definitely possible to reverse engineer the word list and other aspects of the w3w system. However I also want to make my anysis code public and I don't want to deal with w3w's lawyers. w3w make the basic claim that 1. similar addresses are far away from each other and 2. this makes mistakes obvious. 1 isn't true because they use a very naive randomization method. This was described before in an excellent blog post https://cybergibbons.com/security-2/what3words-the-algorithm/ https://cybergibbons.com/security-2/what3words-the-algorithm... I added some equations in my work. In the worst case you end up with a run of addresses like twice.over.x word.again.y repeat.phrase.z ... And maybe 10km away another run like twice.over.a word.again.b repeat.phrase.c ... Only one word is different, which obviously makes it much easier to confuse addresses. The other point is that around 25% of addresses (probably more) could be confused with 4 or more others. In that case, the AutoSuggest feature may not suggest the address you meant, and if it doesn't, there's not much you can do, since this is the only form of error correction available in w3w. w3w is quite popular here in the UK and I can see the appeal, it is more fun to shout out green.apple.regret than some alphanumeric string. But given the above problems (which i am sure w3w know about) that doesn't seem like a good enough reason to trust an app like this with matters of life and death.

heavenlyblue 3y ago

It's a very British startup that clearly has some connection to the government and is trying to lobby their way into NHS etc.