skysight-inc/HackerNews huggingface dataset:
Are trust ratings just raw sums, or can they be based on how much people you trust have rated someone?

For instance, I don't care about how many sockpuppet accounts have endorsed someone, I only care about how they're rated by people I know or trust (or, to a lesser extent, how they're rated by "friends-of-a-friend", though there should be a more than linear decay between each degree of separation.

Also, having publicly (or even privately!) viewable trust ratings can skew the ratings. I might have a true opinion of someone that's better or worse than what I'm willing to publicly announce (we can't all be Zed Shaw ;-). Viewable ratings also create the problem that I might feel pressured to rate someone well so that they won't retaliate against me: let's call this the ebay effect ;-).

There also remains the problem of proving that a given account actually belongs to the person named.

You need to have a posted, credible policy that you won't tamper with or sell ratings, or reveal private information (such as how I really think of so-and-so).

A system like this could be great, but you have to take into account every possible way it could be gamed or cracked, and build in solid defenses against all of them from the very start.
Just code towards your goal. Most of the theory of computer science that you'll need implemented along the way will be done for you via something low-level that you don't really need to worry about because it'll come for free (in python or in django).

If you run into things that you find you're curious about them in a deeper level, that's when you should look for more technical material to support that.
Kevin Rose's Pownce to Launch at Midnight
great! I've got one other person, so that makes 3.

anyone else?
http://www.pragprog.com/titles/rails2 is where I started.
I will in about a month. Coming down from Boston.
You got it right, the idea is to make these trust ratings based on how much people you trust have rated someone. In the alpha version it does not go that far yet, that's the idea though.

I agree that there has to be a good way to prevent how the system can be gamed. We are building those into our design, just haven't had the time to totally add it into the front yet.

Good suggestions. Thanks.
Hey man. One thing you could try, if you're having a tough time with the sheer amount of things to learn out there, is to try to find a project to work on that's going to apply some external pressure on you to solve problems and learn new things. That way, you can sort of chip away at things.
What is it about geeks that turns women off? Is it merely the social maladjustment?

We males tend to adjust our behaviors based on what women find sexy, which is partially why universities used to be male only. Geekiness correlates with good intellectual work, but as mentioned, women don't like it.

Which also makes me think that the key to guiding society is by defining what women find sexy.
The Bitter Homeschooler's Wish List
This site isn't very useful unless a lot of people are using it. [1] Furthermore, the only people with any real motivation to input data are those that want to game the system. How about this as an alternative version 1: a facebook or linkedin app that lets you request a recommendation for a caterer, mechanic, whatever, from your friends. That's useful immediately, and you can aggregate responses.

Also, the people giving me the thumbs-up were beggin for a hurtin.

[1] The current version of your site doesn't care about location, which makes it look less empty but be less useful.
I was in a similar situation and my STRONG advice is to kill it working nights and weekends on your project before you quit. You need tons of inertia...3 things you should have before you quit:

1. some demo/prototypes done
2. a 15 slide business plan
3. one other person that will dedicate him/herself on the level that you are planning.

You will have a newfound appreciation for stability if you do your own company no matter what the economy looks like.
The solution to this problem is simple: stop telling various groups of people what they should do with their lives.

Anyone who has talent and is a hard worker will probably succeed anyway.
Aguri: Coolest Data Structure You've Never Heard Of
I would suggest adding another radio button (e.g. "Company"), inactive if necessary, so there isn't just one People button. Looks a little weird with just one button.

The system looks useful. Not sure if I'd want people to contact me after searching for programmers. You could make sure that the example tag search ("E.g.: Chinese food caterer") returns an entry or that it fits with your targeted audience ("E.g.: PHP programmer").
My favorites are all open source projects, not VC-backed startups who are busy "building something. getting it to the market. fast"

I guess greed and innovation don't match very well.
Thanks - the 120K users is more likely the total number of users for the app - so chances are slim of them all using the site at once - but want to plan for the worst. Might be putting together a license deal and just want to make sure that I don't bankrupt myself.

So - a metric might be 30 concurrent users for 4 mongrels -
4 mongrels per EC2 server.

120 CCU would be 16 mongrels on 4 EC2 servers, etc.

Not that I'd use EC2 - just a convenient constant - load balancing would be tricky.
to live? or to visit?
I'm really trying to figure out how much money serving 120K users is going to cost me in servers and bandwidth.
Thanks for the tips - I've farmed the image uploads out to merbs running in EC2 - there are some other long running (6+ second) tasks that users could perform frequently - I'll start to farm those out as well.
Black Tuesday...01/22/08?
How many users would 100 requests per second translate to? I know it depends on the app, but figuring an average render, think, click cycle - is that 1000 logged in users? 10,000?
The real question is: how the heck are you not making money off of 1000 daily users? Don't tell me this is some social networking BS. If so, just quit now and get half a business plan before starting your next one!
The Coldest Place in the Universe
Is your mama 90 years old? What economic downturn did she live through?
It is... what you make of it.

Enjoy.
The study is discussed in a blog post here, http://bobsutton.typepad.com/my_weblog/2006/08/brilliant_but..., the original reference is Teresa Amabile, "Brilliant but Cruel: Perception of Negative Evaluators," Journal of Experimental Social Psychology, 19 (1983), 146-156.
On-Demand MPI Cluster with Python and EC2
I didn't like the article at all. The use of sophisticated libraries is progress. Now we can think at a higher level, allowing us to quickly prototype new ideas.
I read this article for literally all of 5 seconds before getting pissed off. The answer to this "question" is simple, but you can get 1500 word blog posts voted up for it because nobody wants to hear the answer, which is (1) build a viable startup, and then (2) quit your job. Or! If you're daring and an extremely excellent salesperson, you can try (1) quitting your job and then (2) starting a company.

If you need to think past either of these two strategies before "deciding" whether to start a company, you're not going to start a company.
Also? Arguing for a raise, and then quitting 3 months later after mentally checking out of your job for 3 months? Bit of a dick move.
Radix tries are nice. Use them when

(1) you need fast lookup and fast inserts

(2) you need to preserve the lexicograhpic order of your elements - something that a hash table won't give you

(3) you are afraid of DoS attacks or maybe just "bad" data - hash tables can be attacked easily if the implementation is known

(4) you don't care about memory usage that much.

I compared a simple 8-bit radix tree with some standard hash table implementation - the former took roughly ten times more memory. I then changed my radix to be based on 4 bits (each char is just split into 2 parts) and the memory usage improved twice. Now I'm wondering if radix tries have more room for improvement.

So this is something to consider.

And thanks for the article - never heard of Aguri, it's beautiful.

Upd. sorted lists basically give you same advantages except for fast inserts
9 Reasons Why The Digg Story Sells
Microsoft Discloses Plans For Virtualization Strategy
The iPhone Goes Corporate
Here's a Feedburner feed that was set up almost a year ago. The links to comments are broken in this feed as well, but at least the MIME type is application/rss+xml instead of text/html.

http://feeds.feedburner.com/YCombinatorStartupNews
Yes, it is a dick move. I wrote this post in response to a YCr asking about quitting their job to work on a startup in the face of this possible recession.

Not to be a jaded asshole, but there are many companies that don't really care about their employees and cutback etc to increase profits. Sure 2 wrongs don't make a right, but this raise will fund your company which can care about employees. Also, asking for a raise is empowering and a boost to your self confidence. In my example this comes at a time when you are overworked and a bit uncertain about your future.
Suffix array.
The thing that really amaze me is to see the site have no growth but still it seems a some people return, how is this possible? You have a site that manages to have users visit again and also get some users from search engines, but at the end of the day you still have the same total of users as the day before? it is not logical! (It is a site about cars).
A Conversation About Databases: Stonebraker and Seltzer
The Moral Instinct (by Steve Pinker)
Compressed binary radix tries (also known as PATRICIA trees) give you excellent memory usage characteristics and pretty much optimal search time characteristics: both wins come from only storing the edges corresponding to significant bit differences.

Since hash tables by necessity have to allocate enough storage to keep table load down and minimize collisions, you could find a PATRICIA tree has even better memory footprint than whatever hash table you use.

Of course, all data structures share the DoS problem. There's an input to a PATRICIA tree that pessimizes lookup and memory usage: the one that creates a full 32 bits of fanout for every key. In all cases, the attack degrades performance to linear search.

Of all the "mainstream" data structures, balanced binary trees are probably the hardest to attack this way.
First 37signals, now Tumblr.. Rackspace seems to be getting worse and worse.
Knuth has a pretty good treatment of tries in volume 3.
It's funny that everyone thinks of "the evil company" when they make decisions like this, but never talk about what they're doing to their coworkers.
Does this guy have any credibility? He sure doesn't speak as if his rant is mere conjecture, yet doesn't have any supporting data or even anecdotes. As far as I can tell from the about page, he's a guy with a flaming turd of a startup telling other people how to be successful.

This article seems to be mainly about how to not succeed.
Java "Damaging" Students
Judging from the title, just what hackers need...
Microsoft to Force IE7 Update on February 12th
No Disrespect
The Future of Ideas is now Free
Design Beyond Human Abilities (pdf)
He says binary trees are better default search table than hash table... binary tree search is O(lg(n)) while hash table is O(1)... so hash table is better for search, binary trees win in other ways (like ordered traversal if you need that), but no way you could say one is always better than the other.

Also confused how he proposes to build his Radix Trie in less than linear time... just seems like he ditches his original premise and launches into routing. There are selection algorithms that will find things in an unsorted array in O(lg(n))... but pretty sure building a tree of any sort is not part of it.

Radix Tries are sweet fun... so is just good old Radix Sort, but he starts with something that doesn't really make sense for the topic (the unsorted array he wants to pull three out of), then makes some weird claims, then jumps into routing with Radix Tries... not sure what is insightful here.
D. J. Bernstein uses these too.

http://cr.yp.to/critbit.html
The point of the data structure in this case was not the radix trie alone but rather the combination of the use of tries in concert with the aggregation characteristics of IP traffic. This type of innovative combination is common in the network world due to the necessity of providing ever more introspection and functionality over ever higher throughputs and ever lower latencies. For some serious treatment of the subject, check out the book "Network Algorithmics" by George Varghese.
1/22/08:  Asian markets dropping 5% again?
As a college educated white male, I know all too well how it feels to tread lightly on gender (and race). And since this is Hacker News, I figured there would be lots of debate. When I posted the original question, I just wanted to see if there were any women. So far 2 have spoken up (one appeared to be a lurker who registered to comment on the discussion). I don't know how many total active users there are (~500 who comment?) so I hoped there would be 5-10. Thought it would be cool anyway. Thanks everyone for the great discussion!
Hey Matt,
Good to meet you as well.

Some perspective: I'm not a coder, yet I am starting a web business. I previously founded and grew a non-tech startup to 2 million in revenue in our first 18 months. I fucked it up and made a horrible exit with very little cash.

Currently, I'm on step 5 of the blog post, with a new raise working both a full-time job and a startup company.

I do worry about market risk, so I'm researching several customers for the technology besides the obvious B2C. My biggest concern is a roadblock with google also focusing on the concept for ShelfMade. http://www.techcrunch.com/2007/11/19/google-magazine/

Not to start a fight, but I will be kicking your ass in fantasy football next year. And if ShelfMade has revenue or funding, we'll be doing it on Yahoo fantasy sports, agreed?
One nice thing about being poorish is not having to worry about the markets.

Isn't working on your projects fun?
There aren't any algorithms to find things in an unsorted array in less than worst case linear time. I think you're confusing search (for some value) with select (a value with a given index in the sorted array).
I don't think you could simply replace RoR with java (J2EE) in this particular post. But even if you could: you'd be right to cap on java.

Java makes programming difficult. Some people like that. Many don't.

Ruby makes programming easier. RoR makes doing webapps easier. This guy's premise, that there is no overarching philosophy to RoR, is incorrect, and shows unnecessary ignorance and anger. You have to wonder if he's just projecting.
[insert creative title]
I don't understand. Surely you aren't arguing that you shouldn't ever quit a job because of the way that it will effect your coworkers, are you?
:)

Still, if 2 days in a row of market fall turns into 3 days, then 4 days, then an entire week, we may all have a problem...
I might be biased but http://skribit.com
The question remains in the air: how do I perform more complex queries without SQL? The proposed distributed hash table won't do it.

The article mentioned eBay's scaling PDF offering a link at the bottom. I followed the link read every page of that PDF and have not found any evidence of them abandoning (or minimizing use of) RDBMS. eBay still runs Oracle, but uses in-house built index for listings search, but that's hardly a solution for general problem of running queries more complex than SELECT * FROM Foo WHERE ID=n. Besides NOBODY uses SQL to do complex full-text searches, even small companies I worked for. We used Lucene.

I would love to have a "distributed SQL": scaled-out SQL server in proper sense of the word, capable of running complex SQL queries on distributed sets of data. Hopefully by the time we grow to eBay size someone will innovate in that regard. Or, perhaps, it exists already?
You're correct. Surely I'm not arguing that. That would be a stupid argument. What I am arguing is that deliberately stiffing your employer for a raise while spending all your real cycles building your own company can fuck over your teammates.

Look, you just said you agreed it was a dick move. Great! Do you agree with what you yourself said, or not?
if it snowed in Hotlanta 2 times last week, anything is possible..
This is an awesome, awesome, awesome book. Aguri isn't in it; aguri doesn't even rate for this book. That's how awesome this book is.
Hash tables are NOT O(1). You just failed the job interview.

You're like the 4th person I've seen that read (some) of this article and pulled this tree vs. hash thing out of it. It's a throwaway point. Binary trees provide comparable performance to hash tables, but also provide efficient access to ranges of keys. Binary trees support more operations efficiently than hash tables.

The article isn't about some war I've declared on hash tables.
I think a little bit of context would help.
You know, even with an anonymous account, I don't think I would use the phrase "flaming turd of a startup" unprovoked.
Yes of course. I would guess that you check out YC News or Reddit throughout the workday. Most people take care of personal business or watch funny videos on company time. Nobody works 8 hours straight.

We are describing 2 different employment situations. You are picturing a team environment where everyone has to carry the load to reach a common goal that you feel is meaningful, I'm not. The job I'm thinking of is more like Fight Club or Office Space.

People that have truly team oriented employment where coworkers are working towards a worthwhile goal are less likely to be jumping ship for a startup.

It can be a dick move to the company, but I've seen companies treat people a lot worse.
I am, of course, an idiot; you can't make a PATRICIA lookup worse than O(k).
Global warming my ass.
I'm not trying to prolong this, or be petulant or pedantic, but you don't have to be working for Greenpeace to have dependencies and shared goals. Your project slips 6 months because you were dead wood during dev and QA while you learned Rails, and you just fucked over everyone else whose bonus and raise depended on the project.

We don't have to argue about this because I think we agree.

The more important point is, if you need to come up with an elaborate plan to figure out to engage your new company, you haven't figured out what your new company is. There's a YC meme going around here, along the lines of "is now a good time to start my company?" or "what's the best way to smoothly transition into my new startup?". None of that means shit. 2 months into your startup you are going to face some problem that is going to be an existential threat to your project, and it's all going to go badly, and you're going to have to figure out how to work through it anyways, and all this talk about how to "start the startup" and "milk your last job" is going to sound pretty silly.
You have started with Python. You are already on the right track. Don't stop practicing -- you can't get anywhere without practice.

If you're curious about CS you should just go ahead and read SICP. I recommend the printed version, but the whole thing is online here:

http://mitpress.mit.edu/sicp/

Perhaps there are people who love CS and yet hate this book, but I have yet to meet one. It's not the easiest book in the world, but it is the real thing, and not an imitation.

There are, of course, lots of things you could learn which are not exactly "CS" but which will make you a better web programmer. Study SQL. Study emacs (read Steve Yegge for inspiration) or another killer editor. Learn to use a really decent version control system (the SVN book -- just google "SVN book" to find it -- is easy to understand, but Linus Torvalds is right when he claims that Git is much nicer!) Read "Mastering Regular Expressions". Read Bruce Eckel's Thinking in Java so that you know enough about the world's most popular language to understand where it sucks, ;) and so that you can follow the conversation of much of the rest of the software world. Read K&R.
I thought this was funny.

Of course somebody will come along and be offended because their cousin's sister had bulimia and this kind of thing 'is not funny'.
The first question that comes to mind when I see the front page is, "Why would I use this instead of LinkedIn recommendations? Especially since I don't want to convince everyone I know to switch from LinkedIn, etc.".

It seems like your answer is that trust is weighted by how much you trust someone.

However, that isn't clear without some digging. Certainly, that point is more important than the "thumbs-up" people, yet the "thumbs-up" people are more visible (and annoying).

A couple other questions -

- I'd still need to be sold on getting people I know to sign up - maybe there's some way to piggyback off of existing networks?

- Just because I trust someone in one area doesn't mean I trust them in others. For instance, someone may be a fantastic lawyer, but just because they recommend a developer does not mean I think they're competent to rate developers.

- The tagline, "Your credibility, online" strikes me as a little much. For one thing, the idea of trusting my credibility to a single site gives me the heebie-jeebies. Fortunately, that's not the case, credibility cannot exist in a single database, and thinking about that drives home that the tagline may be overstating it a bit.

- I really dig that the registration form is minimal, but it makes me wonder how to distinguish multiple people with the same name.
"Hash tables are NOT O(1)."

For average lookup time, which is a reasonable context to assume in the preceding comment, yes they are.
What do you mean hash tables are not O(1)?

With a good hash function (collision resistant), the amortized cost of lookup is O(1), even if you need to resize the table.
Be sure to estimate your taxes into the "all other foreseeable expenses" box.

Otherwise this lovely calculator is likely to be 20-40% off :-)
Seems similar to the original intent of rapleaf.com, which is a platform for building reputation. They are actually changing their business model because their product didn't gain any traction. You might want to check that site out, and see if you can differentiate.
Cheers, we agree. I'm not a programmer so I don't have that perspective (probably added to the confusion). As I said on your previous comment, I wrote the post in response to someone asking about quitting their job.

I definitely agree that people asking for random advice on YC about tiptoeing in may be in trouble when problems occur, and they will occur early in the startup.

I'm having the 2 month problems now. If I would have quit my job when I was overly excited earlier in the journey I would be facing some seriously hard times.

Goodluck :)
I have a BS in computer engineering and a MS in computer science... but I've never heard of a "core stack" (a stack trace in a core dump?)... am I one of those "incompetent" graduates?
Homeschooling might be great, but if the author finds it insulting when people suggest they can't teach early grades because the material is so easy it makes me worry that they know nothing about education. I don't think successfully educating young kids has a lot to do with knowing the material or not, past a certain level of familiarity anyway.
The more fundamental problem with colleges is they have no idea how to help people learn. And don't even think that's what they should be doing. No, they want to "teach" students, by which they mean force them to listen to lectures, whether they are interested and learning or not, and force them to do work whether it helps them individually or not, and force them to take tests to make sure they obeyed.