physcab

The banning of liquids and pastes are logical. There are some extremely volatile liquid and plastic explosives that would take your leg off if you dropped [1][2]. Or if they were used as primary explosives to ignite a more powerful secondary explosive. That could be disastrous if TSA allowed liquids in larger quantities.

As for the detection technologies that are currently out on the market, all I have to say is that every single one of them can be confused and circumvented, which is why they have seemingly arbitrary rules. For example, xray technologies can easily confuse plastic explosives with a piece of cheese, which is why you have to take shit out of your bag. MMW wave technologies are confused by water substances, which is why you have to do a pat down if an anomaly is detected.

My own technology that I worked on was primarily developed as a low-cost surface technique, so if you had explosive residue on your hands or baggage our detector would alarm.

[1]http://en.wikipedia.org/wiki/Nitroglycerin [2]http://www.youtube.com/watch?v=oa6fcun3kag

- Barter still exists even though players are more sophisticated. Author expected to find one item becoming defacto currency, but that does not happen.

- Because barter exists, you can express the price of items relative to other items in the game, ie 1 lazer gun = 2 hats. It is theoretically possible to start with 2 hats and end up with 6 through multiple trades of items.

- Author then extrapolates a model for an economy like TF2 that has 35k items and 600M relative prices.

- TF2 is not in equilibrium, meaning lots of opportunity for arbitrage. Arbitrage opportunities are greatest when new items and sales are introduced.

- Assuming this "dis-equilibrium", author adjusts the model by accounting for frequency of trades, ie 1 lazer gun = 2 hats but may only be traded a few times, but lets say a new item, earmuffs, are added to the game and conversion rate is 3 earmuffs = 2 hats. This might be traded many times by players due to its introduction and inherent value to them.

- You can graph the value of these items over time to see if they can be arbitraged.

- My knowledge of statistics is rather weak, but it looks like if you compute the error rate, ie square root of the differences between normal model and adjusted model, you can monitor with real time data when arbitrage opportunities arise.

Grand summary: Gaming companies produce a ton of real time transaction data, and with this data it is possible to monitor economy dynamics in new ways that economists have previously been unable to do. If players had access to this data they can arbitrage more effectively, but more importantly for game designers it might be worthwhile to be knowledgeable about these effects so they can keep players engaged in the long term.

I'm not sure why you'd immediately jump to the conclusion that employees would be looking for another job. That's something which may be completely out of your control (whether they're bad, good, happy, or disgruntled at their job) so why worry about it?

You're also making this hypothetical "improve or else" conversation more negative than I see it happening. Like I said, in grad school, when I failed my quals the first time the committee gave me constructive feedback. Sure, I could have been like "fuck this" and went to a different school, but then again, I knew the rules when I signed up and I chose to honor them. I also felt like their feedback was reasonable. It was nothing personal and when 5 people agree on something, its easy to see where you came up short. I also had a chance to rebuttal if I thought their grading was wrong.

Secondly, failing my quals gave them a chance to help me. Previously I thought I knew what to do on my own, so I never bothered them with questions. Afterwards, I clearly saw the mismatch in expectations, so I pestered them until I was sure the answer they were looking for was the one I was spending my time on figuring out.

If you're envisioning a one-way "improve or else" conversation taking place, then yeah, I agree with you. But this should be a dialog where both parties are willing to admit they were in the wrong.

However, let's not overlook the fact that there are a proportion of managers who view termination as both the start and the end of the process with no conversation taking place. I think that's the "at will" part of the "at will termination" clause everyone signs. And I have a sneaking suspicion that this proportion is much larger than we might hope to think.

This is a question that no one seems to get right, unless its fairly obvious. If they stole something, no brainer. If they sexually harassed an employee, should be a no brainer. And if the company is in a financially distressed position, it may be unpleasant to fire someone, but atleast its understandable. What if the company is healthy and employee did nothing obviously wrong?

Then I guess, you look at the quality of their work. But judging quality is subjective, and you're likely to have a sliding scale depending on employee's past experience and delta to their start date. And what about periodic reviews? What about quarterly objectives? What about what other employee's think? How long do you warn an employee before you go ahead with it?

I think one of the better ways of dealing with firing is how it was handled in grad school. At my school, you had a series of qualifying examinations and you had a committee. The rules were pretty clear: 2 chances to pass and if not, goodbye. One of the tests was an oral examination in front of the committee of 5. There weren't any clear answers, but the committee would convene and in an hour they'd have a decision with lots of feedback. I failed my first attempt. But guess what? After that, I honed in on their feedback, worked my fucking ass off and passed my second attempt with flying colors.

I don't see this happening at many (or any) companies. I'm not sure why, but IMHO employers use the "at will termination" too liberally. Either that, or they let the bad employees stay far too long. Sometimes I wonder if a second chance would help bubble good employees to the top when you had previously mis-classified them as bad or vice versa. Firing scares the shit out of people...why not make this process less of a surprise than it has to be.

Whether you realize it or not, FB changes your emotional health. FB used to make me oddly depressed. Its like sitting in front of the TV and feasting on Sour Patch Kids for two hours. I would sit there staring at how awesome people's lives were and wonder why I wasn't doing such awesome things myself. I heard about the passing of family members from family friends before family members would have a chance to tell me personally.

After I stopped going to FB my important friends started CALLING me. Can you believe that? They picked up the phone and CALLED me. I went out to dinner more. I stopped engaging in those destructive conversations like "Can you believe so-and-so's status message..."

There have been some drawbacks though. I don't always hear about last-minute parties. I don't get to see the pictures my friends take from events. And I don't have the luxury of sending a message to someone I don't quite know very well who wouldn't have my phone number or e-mail, most likely through group activities like Crossfit that I'm a member of.

But all things considered, ditching Facebook is highly recommended.

The real question is the value of their users, and whether Zynga can increase that value. Zynga's largest expense is probably marketing and CPI costs have more than likely doubled (I don't know the exact numbers) on Facebook over the past couple years. If Zynga hasn't increased the value of their users, that means they can acquire less, thus the drop in DAU.

The key equation for a free-to-play business is LTV > Acquisition. Unfortunately, CPI for FB probably somewhere around $1 and on iOS it can be $1-$5 depending on who's buying the traffic that day. This is why the social game market is difficult to survive in, because most small companies don't have the marketing spend to acquire customers at that cost. For Zynga, these costs are starting to show in reduced DAU, due to a combination of natural declining retention and an increase in acquisition costs.

I'm curious to know how you see the product benefiting people. What do you see people actually using it for?

Right now it seems like a cute demonstration of a data mashup though not entirely factually correct. For example, if I search for "Coldplay" it says 85% affinity for Asian Indian and 82% Plastic Surgery and high Z-score for Hindi? How do you ensure the accuracy of this data?

I think you need to display the results of this data differently to users. If its correct, people without statistics backgrounds will get confused because not everyone can interpret what a z-score means, nor will they understand how it is useful to them.

Because if you're going to go there, then its equally as harmful spending time away from your friends and family in front of a computer screen, especially when you consider the fact that you don't need any money to do it.

"Yes StarcraftII, I will gladly give you $50 and hundreds of hours of my life away, but thank god you're way more ethical of a game than that one that takes up 2 minutes of my bus ride and cons me into spending $1.99 on my way to work"

Addiction is everywhere. Its a sad fact of life. There are people who are addicted to shopping, but Macy's doesn't turn away repeat customers. There are people addicted to food, but Olive Garden/ McDonalds doesn't turn away morbidly obese people. There are people addicted to drinking, but Safeway doesn't do a health scan and deny these people from buying liqour. Similarly, I wouldn't expect Zynga or Blizzard to be like "hey, you've spent $10k/1000 hours on my game, why don't you go see your family or put your money to better use".

They still have issues with: Loading times, graphics rendering, max population limit to rooms, difficulty to "level up" and get more DJ points, stupid room rules

Things that give me hope: Cool iphone app, easy sharing, STILL discovering new music off of it, pretty awesome guest DJ's (I'm a house/mashup nut and they had DJ Aoki and 3LAU)

- beautiful

- ninja

- rockstar

- web 2.0

- social-mobile-local

- ajaxified

- "I have an idea for an iphone app"

- gamification

- hyper-local

What is most illuminating for a chart like this is seeing these numbers as a total % of activations/daily users/daily visitors over time. That way, you can see if a particular change you made (such as doing some landing page optimization) actually increased conversions which is ultimately what you're trying to look at in something like this.

You want to know another way to hide illicit items in those body scanners? Surround the items in water.

There are also certain materials that give off false positives and most likely the software will scan the image response against a bank of known materials. I wrote pattern detection software that did just this. Oddly enough, cheese is one of them. So stick your knife in a nice big piece of cheddar and you might make it through just fine.

This is pretty common in the tech industry as I've come to realize. The issue is that many people can be good at programming, and hell, they might even have open source projects or even shipped applications to show for it. But put them in a software engineering interview where they have to walk through a basic dynamic programming or data structures problem and they will probably stumble. This situation is even more likely for interdisciplinary individuals where they don't have typical degrees for their field of interest.

So, point being, it takes a while to find a good fit. One where your skills expectations are agreeable for both sides. I don't see advertising on HN an issue, since we are the target market for this type of situation, but so long as it doesn't become a job board.

Targeting is your word, not mine. We cohort users by spending activity and learn from them in the same way a Macy's buyer will learn from their most loyal customers. My friend works as a buyer for children's clothes and they make the same business decisions I make about inventory and store layout.

We maximize for users who spend large amounts of money (incidentally none of ours have spent $10k, more like $100) because this and engagement data is the only data we have in determining customer loyalty. So we ask ourselves questions like "If this user found enough value out of this feature to spend $100 on it, we should make more like this".

You and I also know that this isn't a problem inherent to just casual mobile games. It's a chronic problem to the gaming industry as a whole, and its not going to stop people from making entertainment for the millions of users who aren't addicts.

I have friends who play Starcraft II a couple hours a day. I've known people who will skip work and play 8 hours a day. I've seen a 60 minute story on someone who was addicted to World of Warcraft. This is a chronic problem of the industry as a whole, but its not a reason to stop making games because the majority of users can have fun responsibly.

So even though I don't believe in it (I deactivated FB for this reason), I'm not sure how much financial benefit you can gain from <UserID> <StrawberryFarmID> TSV files which most of this data is anyways.

I came from a web company. I was a data analyst there too. But I really wanted to work in the mobile industry and figure out how to deliver insights on a completely new platform also at massive scale as well.

The question that confronts me when I go into work everyday is how can we make this game fun for everyone, and how can we make money in a non-destructive, ethical manner?

Would you feel the same way if we changed the business model from virtual currency to a fixed-cost one?

But more importantly, its learning how to be a detective. For example, I'm not strictly a math person. I also know Python and PHP and use it to write scripts when I need to validate a theory, often working with raw logs.

You also need business acumen. Analysts are like consultants in that they work with a variety of teams and stakeholders. Everyone wants to be sure that the decision they're making is the right one, and data can help them do it. So you need an understanding of what the core issue is, how the stakeholder wants it solved, and the engineering capability to get it done in a timely fashion.

One of my favorite books is Collective Intelligence. Its a soft-intro to machine learning, and having read that and gone through those exercises along with taking a formal class on machine learning, has helped me see the importance of statistics applied at web scale.

EDIT (to the PS): I don't think there's a standard teaching for data science. Everyone screens for it differently. If you apply for a job as a data scientist at LinkedIn for example (I did) they'll expect you to have a fairly formal CS background and will throw you questions any good software engineer should be able to solve. But they also ask you questions like "design a news feed" or "whats a good algorithm for a spam filter and how do you score it" or "how do you make an algorithm work with little data". I think "data science" is actually learning how to apply statistics at web scale problems, so my advice would be to look at things like recommenders, spam filters, classifiers, NLP, etc.

I'm obviously aware of what goes on in the industry and its similarities to gambling are something I think about a lot. But as an analyst, I feel like I have a lot of power in helping to create games that are fun and engaging, plus learning how to drive a product to be successful. I don't think of it as a spam machine or a front for taking money from the poor.

Maybe the business model needs to be changed. If its virtual currency that makes it creepy, then maybe switching to a fixed-cost product is something the industry as a whole needs to move to. We're still in the infancy here in learning how to harness mobile devices to make better products.