Hashing for the Homeless(causes.github.io)
causes.github.io
Hashing for the Homeless
http://causes.github.io/blog/2013/06/04/hashing-for-the-homeless/
4 comments
> Do homeless people have a single canonical name that they will use consistently?
They have an identity.
> Is it fair to request that they structure their day around a hashing algorithm that they don't understand?
It is not fair that they are homeless. It is not fair that the best thing for many of them to do is to stand in line starting at 3AM the previous day to get a bed for a night. It is fair to offer them a fair chance at a shower in a predictable way. Rather than standing in line for hours in hopes of a shower, they can come and maybe get a shower... or not. Unfortunately, rationing is necessary.
The tokens idea is interesting, but the meaning of them is a good bit more abstract than remembering a single time. Also, things get lost, and keeping things is pretty hard when you're homeless - basically everything you hope to keep has to be carried with you at all times.
They have an identity.
> Is it fair to request that they structure their day around a hashing algorithm that they don't understand?
It is not fair that they are homeless. It is not fair that the best thing for many of them to do is to stand in line starting at 3AM the previous day to get a bed for a night. It is fair to offer them a fair chance at a shower in a predictable way. Rather than standing in line for hours in hopes of a shower, they can come and maybe get a shower... or not. Unfortunately, rationing is necessary.
The tokens idea is interesting, but the meaning of them is a good bit more abstract than remembering a single time. Also, things get lost, and keeping things is pretty hard when you're homeless - basically everything you hope to keep has to be carried with you at all times.
If I had to quickly assign numbers to buckets using a hash table would be obvious but I would never have thought of using the same ideas for assigning people to lines.
This reminds me of a joke I once heard - if you want the cold soda you need to get to the one in the back of the fridge. That's what you get for implementing the fridge as a stack.
Data structures are all around us, we just need to recognize it.
This reminds me of a joke I once heard - if you want the cold soda you need to get to the one in the back of the fridge. That's what you get for implementing the fridge as a stack.
Data structures are all around us, we just need to recognize it.
You won't believe this, but we actually have a soda fridge here that has a deque implementation on the door with a note that cold ones will be at the back.
I'll provide a pic if demanded. ;)
I'll provide a pic if demanded. ;)
That, I need to see.
OK, I misremembered, it's a queue, not a deque. Still:
http://imgur.com/a/Yujev#0
Also kinda random since we don't use much Java here. I do like that people debugged it, though.
Also kinda random since we don't use much Java here. I do like that people debugged it, though.
I've been meaning to cross out the "synchronized" there. It's unnecessary since Queues are already threadsafe.
It's an interesting idea but I don't think the ID problem is as trivial as the proposal makes it. For example,
http://www.nlchp.org/content/pubs/Photo%20ID%20Barriers1.pdf
http://www.nlchp.org/content/pubs/Photo%20ID%20Barriers1.pdf
By "ID", I don't mean government-issued photo ID, necessarily - just the ability to know how a person is will do.
It may be that the person is a repeat user so that the staff recognizes them, or it may be that someone else can vouch for them. And some will have photo IDs, too. ;)
It may be that the person is a repeat user so that the staff recognizes them, or it may be that someone else can vouch for them. And some will have photo IDs, too. ;)
Author here if people have feedback.
I think you're missing the point about homelessness.
In most parts of the US you can get social services if you're willing to (1) deal with horrible bureaucracy, and (2) stop using drugs and alcohol.
Chronically homeless people aren't homeless because they're poor but instead they have mental health issues that leave them disconnected from avenues for help. There are many "homeless" people that don't sleep on the street because they stay with friends or family, or, like William Shatner in the early 70's, live in a car.
Because the chronically homeless have bad enough problems relating to people they don't need complicated rules coming between them and services they need.
In most parts of the US you can get social services if you're willing to (1) deal with horrible bureaucracy, and (2) stop using drugs and alcohol.
Chronically homeless people aren't homeless because they're poor but instead they have mental health issues that leave them disconnected from avenues for help. There are many "homeless" people that don't sleep on the street because they stay with friends or family, or, like William Shatner in the early 70's, live in a car.
Because the chronically homeless have bad enough problems relating to people they don't need complicated rules coming between them and services they need.
> In most parts of the US you can get social services if you're willing to (1) deal with horrible bureaucracy, and (2) stop using drugs and alcohol.
To even have a chance of being loosely correct, the "willing" here needs to change to "willing and able". For both items, that is a pretty big difference from just "willing".
To even have a chance of being loosely correct, the "willing" here needs to change to "willing and able". For both items, that is a pretty big difference from just "willing".
I'll agree with that.
A fair number of homeless have mental conditions, but not nearly all. In any case, the hashing approach doesn't manifest as complicated: What's your name? OK, come at 10:15 on Wednesday. That's all.
Hi thanks for the article. Have you actually implemented this system or are in the process of implementing it?
I think the article is much more interesting if it's more than just an in principle idea. Also out would be nice if the article made that clearer in either case
I think the article is much more interesting if it's more than just an in principle idea. Also out would be nice if the article made that clearer in either case
Is it fair to request that they structure their day around a hashing algorithm that they don't understand?
There's an arbitrary kind of "command" oriented aspect to this that I'm not crazy about. Sort of a "the algorithm says that you go here at time X" element that is inscrutable and will no doubt inspire a lot of theories about how it's rigged ("Hispanic names always get to go in the morning, did you notice?").
I would suggest colored tokens that are good for certain timeslots: Red might mean "Monday at 9, Tuesday at 10, ...". I don't know if they are persistent or good for one use or both. The tokens can be recollected so you know how many are circulating for a given time/place and can avoid oversubscription.
These could be handed out at random and traded among the clients so they can put together a schedule that suits them. This removes the "arbitrary computer says so" kind of element of the hashing scheme.