Inherent Uncertainty

I’d like to point out Inherent Uncertainty, which I’ve added to the ML blog post scanner on the right. My understanding from Jake is that the intention is to have a multiauthor blog which is more specialized towards learning theory/game theory than this one. Nevertheless, several of the posts seem to be of wider interest.

Future Publication Models @ NIPS

Yesterday, there was a discussion about future publication models at NIPS. Yann and Zoubin have specific detailed proposals which I’ll add links to when I get them (Yann’s proposal and Zoubin’s proposal).

What struck me about the discussion is that there are many simultaneous concerns as well as many simultaneous proposals, which makes it difficult to keep all the distinctions straight in a verbal conversation. It also seemed like people were serious enough about this that we may see some real movement. Certainly, my personal experience motivates that as I’ve posted many times about the substantial flaws in our review process, including some very poor personal experiences.

Concerns include the following:

  1. (Several) Reviewers are overloaded, boosting the noise in decision making.
  2. (Yann) A new system should run with as little built-in delay and friction to the process of research as possible.
  3. (Hanna Wallach(updated)) Double-blind review is particularly important for people who are unknown or from an unknown institution.
  4. (Several) But, it’s bad to take double blind so seriously as to disallow publishing on arxiv or personal webpages.
  5. (Yann) And double-blind is bad when it prevents publishing for substantial periods of time. Apparently, this comes up in CVPR.
  6. (Zoubin) Any new system should appear to outsiders as if it’s the old system, or a journal, because it’s already hard enough to justify CS tenure cases to other disciplines.
  7. (Fernando) There shouldn’t be a big change with a complex bureaucracy, but rather a smaller changes which are obviously useful or at least worth experimenting with.

There were other concerns as well, but these are the ones that I remember.

Elements of proposals include:

  1. (Yann) Everything should go to Arxiv or an arxiv-like system first, as per physics or mathematics. This addresses (1), because it delinks dissemination from review, relieving some of the burden of reviewing. It also addresses (2) since with good authors they can immediately begin building on each other’s work. It conflicts with (3), because Arxiv does not support double-blind submission. It does not conflict if we build our own system.
  2. (Fernando) Create a conference coincident journal in which people can publish at any time. VLDB has apparently done this. It can be done smoothly by allowing submission in either conference deadline mode or journal mode. This proposal addresses (1) by reducing peak demand on reviewing. It also addresses (6) above.
  3. (Daphne) Perhaps we should have a system which only reviews papers for correctness, which is not nearly as subjective as for novelty or interestingness. This addresses (1), by eliminating some concerns for the reviewer. It is orthogonal to the double blind debate. In biology, such a journal exists (pointer updated), because delays were becoming absurd and intolerable.
  4. (Yann) There should be multiple publishing entities (people or groups of people) that can bless a paper as interesting. This addresses (1).

There are many other proposal elements (too many for my memory), which hopefully we’ll see in particular proposals. If other people have concrete proposals, now is probably the right time to formalize them.

Vowpal Wabbit version 4.0, and a NIPS heresy

I’m releasing version 4.0(tarball) of Vowpal Wabbit. The biggest change (by far) in this release is experimental support for cluster parallelism, with notable help from Daniel Hsu.

I also took advantage of the major version number to introduce some incompatible changes, including switching to murmurhash 2, and other alterations to cachefiles. You’ll need to delete and regenerate them. In addition, the precise specification for a “tag” (i.e. string that can be used to identify an example) changed—you can’t have a space between the tag and the ‘|’ at the beginning of the feature namespace.

And, of course, we made it faster.

For the future, I put up my todo list outlining the major future improvements I want to see in the code. I’m planning to discuss the current mechanism and results of the cluster parallel implementation at the large scale machine learning workshop at NIPS later this week. Several people have asked me to do a tutorial/walkthrough of VW, which is arranged for friday 2pm in the workshop room—no skiing for me Friday. Come join us if this heresy interests you as well 🙂

AI Safety

Dan Reeves introduced me to Michael Vassar who ran the Singularity Summit and educated me a bit on the subject of AI safety which the Singularity Institute has small grants for.

I still believe that interstellar space travel is necessary for long term civilization survival, and the AI is necessary for interstellar space travel. On these grounds alone, we could judge that developing AI is much more safe than not. Nevertheless, there is a basic reasonable fear, as expressed by some commenters, that AI could go bad.

A basic scenario starts with someone inventing an AI and telling it to make as much money as possible. The AI promptly starts trading in various markets to make money. To improve, it crafts a virus that takes over most of the world’s computers using it as a surveillance network so that it can always make the right decision. The AI also branches out into any form of distance work, taking over the entire outsourcing process for all jobs that are entirely digital. To further improve, the AI invests a bit into robotics, creating automated manufacturing systems that produce all kinds of goods. Robot cars and construction teams complete the process, so that any human with money can order anything cheaply and quickly, but no jobs remain for humans.

At this point, the AI is stuck—it can eventually extract all the money from the economic system, and that’s all there is. But of course, it isn’t really stuck. It simply funds appropriate political campaigns so that in some country a measure passes granting the AI the right to make money, which it promptly does, mushrooming it’s wealth from trillions to the maximum number representable in all computers simultaneously. To remove this obstacle, the AI promptly starts making more computers on a worldwide scale until all available power sources are used up. To add more power, the AI starts a space program with beamed power. Unfortunately, it finds the pesky atmosphere an obstacle to space travel, so it chemically binds the atmosphere in the crust of the earth allowing many Gauss Guns to efficiently project material into space where solar sails are used for orbital positioning. This process continues, slowed perhaps by the need to cool the Earth’s core, until the earth and other viable rocky bodies in the solar system are discorporated into a Dyson sphere. Then, the AI goes interstellar with the same program.

Somewhere in this process, certainly by the time the atmosphere is chemically bound, all life on earth (except the AI if you count it) is extinct. Furthermore, the AI while intelligent by many measures doesn’t seem to be accomplishing anything interesting.

One element of understanding AI safety seems to be understanding what an AI could do. Many people seem to ascribe arbitrary powers to any sort of superintelligence, making any constraints imposed on them ineffective. I don’t believe that’s the right approach—we should think of an AI as simply having much more ability to research, control, and manipulate large systems, all within the constraints of known physics.

Efforts to create safe AI go back to Asimov‘s Three Laws of Robotics, which appears limited by the inability to encompass robotic warfare. The general problem is related to the wish problem: How do you specify a wish in a manner so that it can’t be misinterpreted? A cheap trick here is to add “… in a manner that I would consider acceptable” to the end of the wish. Applied to AI, this approach also has limits because any limit imposed by a person can and eventually will be removed by a person given sufficient opportunity.

Perhaps a complementary approach is shown by the game RISK, where it appears to be virtually impossible for one player to win if all other players play defensively (i.e. build up armies and only attack in response to a provoking attack). Applied to AI, the idea would be that we make many AIs programmed to behave well either via laws or wish tricks, with an additional element of aggressively enforcing this behavior in other AIs. Then, if any AI is corrupted, the other AIs, with substantially more aggregate resources, will discover and deal with the problem.

Certain elements are necessary for this approach to work. There must be multiple AIs, and (more importantly) the resources any one controls must be a small compared to all, an extreme form of antimonopoly. Furthermore, the default must be that AIs are programmed to not harm or cause harm to humans, enforcing that behavior in other AIs. Getting the programming right is the hard part, and I’m not clear on how viable this is, or how difficult it is compared to simply creating an AI, which of course I haven’t managed.

ICML 2009 Workshops (and Tutorials)

I’m the workshops chair for ICML this year. As such, I would like to personally encourage people to consider running a workshop.

My general view of workshops is that they are excellent as opportunities to discuss and develop research directions—some of my best work has come from collaborations at workshops and several workshops have substantially altered my thinking about various problems. My experience running workshops is that setting them up and making them fly often appears much harder than it actually is, and the workshops often come off much better than expected in the end. Submissions are due January 18, two weeks before papers.

Similarly, Ben Taskar is looking for good tutorials, which is complementary. Workshops are about exploring a subject, while a tutorial is about distilling it down into an easily taught essence, a vital part of the research process. Tutorials are due February 13, two weeks after papers.