trentmkelly/LessWrong-43k huggingface dataset:
Understanding Machine Learning (II)
by Rafael Harth — 2019-12-22T18:28:07.158Z

This is part 2 of a three part series on the fundamentals of Machine Learning as presented by this book. It builds heavily onto part I.

Uniform Convergence

Uniform convergence is a property which a hypothesis class may satisfy that will end up being equivalent to PAC learning, and the ability to use either definition whenever needed will be quite useful. "Uniform convergence" means convergence with respect to the difference between the empirical error and the real error, which is uniform with respect to all hypotheses in the class – i.e. we can bound the difference between real and empirical error across all hypotheses simultaneously. We have the following formal definition:

A hypothesis class H has the uniform convergence property iff there is a function u∗:(0,1)2→N such that, for every probability distribution D over X×Y, every gap ϵ∈(0,1) and every confidence level δ∈(0,1), if |S|>u∗(ϵ,δ), then with probability at least 1−δ over the choice of S, the inequality |ℓS(h)−ℓ(h)|≤ϵ holds for all h∈H.

Recall that PAC learnability demands that the true error of the hypothesis output by AERM is low. On the other hand, uniform convergence demands that the gap between the empirical and the true error is low. Unsurprisingly, both properties are equivalent. We will prove one direction now, namely that uniform convergence implies PAC learnability.

Suppose the uniform convergence property holds for values ϵ,δ. We apply AERM to our task, feed it our training sequence S which fulfills the property that |S|>u∗(ϵ,δ), and now want to argue that the true error of AERM(S) is not much higher than the true error of some h∗∈argminh∈H[ℓ(h)]. The uniform convergence property does not allow us to compare both errors directly, rather, we can argue that ℓ(AERM(S))−ℓS(AERM(S))≤ϵ because of uniform convergence, that ℓS(AERM(S))−ℓS(h∗)≤0 because of what AERM does, and finally that ℓS(h∗)−ℓ(h∗)≤ϵ because of uniform convergence. Putting these three inequalities together, we do indeed obtain a bound on ℓ(AERM(S))−ℓ(h∗), but it is 2ϵ not ϵ. The c... ,,
The Towel Census: A Methodology for Identifying Orphaned Objects in Your Home
by mingyuan — 2019-12-22T06:04:44.111Z

Background: I live at Event Horizon, a rationalist house that for much of its history housed so many short-to-medium-term guests that many people thought of it as a rationalist hostel. We've developed a number of useful systems over the years, and while I don't have reason to believe our methods are entirely novel, I've still always thought it would be nice to share them. I'll be doing so in bite-sized posts like this over the coming months.

In this first post, I introduce a simple and versatile tool: the Towel Census.

Because we had so many guests using our house towels, and because there were too many of us to keep track of, about once a month we would end up in a state where all the towels were hanging up in the bathroom, dirty, and no one was sure which ones were in use. To solve this, we invented the Towel Census. The steps are simple:

Someone goes around and puts a piece of blue tape on every towel in the house.
The towel census is announced in Slack (which is our central channel for house communications), and a deadline for removing the tape is given (usually 48 or 72 hours out).
Residents remove tape from towels that they are currently using. If out of town, residents can ask via Slack for their tape to be removed.
When the deadline is up, the censor gathers all the towels that still have tape on them, washes them, and puts them away with the guest towels.

On average, we'd do a towel census every two months, and find 10-15 unclaimed towels each time.

The same process can be used to identify other unclaimed items, such as shoes, jackets, toiletries, and food in the fridge that no one wants anymore.

Variant: Instead of putting tape on every item, just move all of the items, and have people put back the ones that belong to them. This can be better than tape in some cases, e.g. for toiletries since they’re small and likely to get wet.

Thanks for reading, and let me know if you have any questions or confusions :)
Pixel 3a Review
by jefftk — 2019-12-22T03:00:02.105Z

About a month ago I replaced my first-generation Pixel phone with a
Pixel 3a, and the 3a is as close to my ideal as I've had:

Top-quality camera

Solid battery life

Near-stock Android

Fingerprint sensor

Headphone jack

Relatively cheap ($300)

Several years ago, phones got good enough at most things that the
extra money for a "flagship" phone [1] felt like it didn't make sense.
What held me back was the camera: I take a lot of pictures and really enjoyed how much better phone
cameras were getting. The 3a changed this: it has the same excellent
camera (and camera software) from the Pixel 3, decoupled from the
other choices that made the 3 expensive.

In general the tradeoffs on the 3a are ones I'm ok with: it's a bit
thicker, the black is plastic (which I cover with a case anyway), it
doesn't have wireless charging (which I don't use), it has a slightly
slower CPU, it doesn't have an ultra-wide selfie camera (which I
wouldn't use), isn't water resistant, and has slightly less fancy
glass. On the other side, it has a slightly larger screen, a slightly
larger battery, and a headphone jack.

The battery life has probably been the largest immediate improvement
for me, but that's mostly just going from a two-year old phon to a new
one. Still, it's pretty
great having 50%+ battery left at the end of each day.

The other thing I've noticed is a pretty minor UI thing: holding down
the camera button takes a video instead of a burst. While I'm not
sure what this means for my kids' pages it is really
convenient when I want to jump right into taking a short video. It's
possible that there's also some sort of hardware change that enables
this, since I remember previous phones taking longer to get into video
mode.

Overall I'm very happy with it, and would recommend it to other people
who see the tradeoffs involved the same way I do.

(Disclosure: I work for Google, who makes this phone)

[1] My past phones, all the cheapest version of the flagship phone from
their manufacturer at the time: Galaxy SII, Moto X, Galaxy S6, Pixel.

Comment via: facebook
Section 7: Foundations of Rational Agency
by JesseClifton — 2019-12-22T02:05:24.380Z

This post is part of the sequence version of the Effective Altruism Foundation's research agenda on Cooperation, Conflict, and Transformative Artificial Intelligence.

7 Foundations of rational agency

We think that the effort to ensure cooperative outcomes among TAI systems will
likely benefit from thorough conceptual clarity about the nature of rational agency. Certain foundational achievements — probability theory, the theory of
computation, algorithmic information theory, decision theory, and game theory to
name some of the most profound — have been instrumental in both providing a
powerful conceptual apparatus for thinking about rational agency, and the
development of concrete tools in artificial intelligence, statistics, cognitive science, and so on. Likewise, there are a number of outstanding foundational questions surrounding the nature of rational agency which we expect to yield additional clarity about interactions between TAI-enabled systems. Broadly, we want to answer:

What are the implications of computational boundededness (Russell and Subra-manian, 1994; Cherniak, 1984; Gershman et al., 2015) for normative decision theory, in particular as applied to interactions among TAI systems?

How should agents handle non-causal dependences with other agents’ decision-making in their own decisions?

We acknowledge, however, the limitations of the agenda for foundational questions which we present. First, it is plausible that the formal tools we develop will be of limited use in understanding TAI systems that are actually developed. This may be true of black-box machine learning systems, for instance [1]. Second, there is plenty of potentially relevant foundational inquiry scattered across epistemology, decision theory, game theory, mathematics, philosophy of probability, philosophy of science, etc. which we do not prioritize in our agenda [2]. This does not necessarily reflect a considered judgement about all relevant areas. However, it is plausible to us that the research directions listed here are among the most important, tractable, and neglected (Concepts,n.d.) directions for improving our theoretical picture of TAI.

7.1 Bounded decision theory [3]

Bayesianism (Talbott, 2016) is the standard idealized model of reasoning under empirical uncertainty. Bayesian agents maintain probabilities over hypotheses; update these probabilities by conditionaliza

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Templates and videos for doing annual and daily reviews 
by peterslattery — 2019-12-22T00:48:53.832Z

Many individuals and organisations in the rationality community do an "annual review" (a review of the past year and update of future plans).

In the past I couldn't find a ready made document to complete to undertake my own annual review. Alex Vermeer's stuff was good but not quite ready to use in my opinion.

With that in mind, I am sharing an annual review/planner template that I made in google sheets.

It incorporates Alex Vermeer's questions and a few of my own. I also added some sheets to add goals and track ‘bugs’.

Please feel free to copy, share and modify it.

Annual review template
http://bit.ly/2MhHc0W
https://lnkd.in/guY8EDW

Over the past year I have also used a 'daily tracker' sheet to help identify and understand patterns of mood and behaviour and to help me to implement and track my goals

Daily tracker template and video
http://bit.ly/3rOscb9
https://lnkd.in/gi6aEQk
Old and New Saw Blades
by jefftk — 2019-12-21T02:00:01.545Z

Five years ago I bought a used Model 77 Skilsaw. I've used it for a

bunch of

house

projects, and it's very
versatile. I noticed that it was starting to be more work to cut
things and I was getting some burning and smoking, so I decided to put
on a new blade. Here's the last cut with the old blade:

And the first cut with the new one:

You can see that the old one is much rougher, where the saw has torn
its way through the wood. The rings are raised, because the dull
blade has torn out more of the soft earlywood the harder latewood.
The edges are splintered and there are burn marks. On the other hand,
the new one is smooth, because the blade was sharp enough for a clean
cut. No burning, minimal splintering. It was also a much quicker and
easier cut.

Mostly this is to say, sawblades are not that expensive or difficult
to change, and I should have replaced this one sooner!
The Counterfactual Prisoner's Dilemma
by Chris_Leong — 2019-12-21T01:44:23.257Z

Updateless decision theory asks us to make decisions by imagining what we would have pre-committed to ahead of time. There's only one problem - we didn't commit to it ahead of time. So we do we care about what would have happened if we had?

This isn't a problem for the standard Newcomb's problems. Even if we haven't formally pre-committed to an action such as by setting up consequences for failure, we are effectively pre-commited to whatever action we end up taking. After all the universe is deterministic, so from the start of time there was only one possible action we could have taken. So we can one-box and know we'll get the million if the predictor is perfect.

However there are other problems where the benefit accrues to a counterfactual self instead of to us directly such as in Counterfactual Mugging. This is discussed in Abram Demski's post on all-upside and mixed-upside updatelessness. It's the later type that is troublesome.

I posted a question about this a few days ago:

If you are being asked for $100, you know that the coin came up heads and you won't receive the $10000. Sure this means that if the coin would have been heads then you wouldn't have gained the $10000, but you know the coin wasn't heads so you don't lose anything. It's important to emphasise: this doesn't deny that if the coin had come up heads that this would have made you miss out on $10000. Instead, it claims that this point is irrelevant, so merely repeating the point again isn't a valid counter-argument.

A solution

In that post I cover many of the arguments for paying the counterfactual mugger and argue that they don't solve it. However, after posting, both Cousin_it and I independently discovered a thought experiment that is very persuasive (in favour of paying). The setup is as follows:

Omega, a perfect predictor, flips a coin and tell you how it came up. If if comes up heads, Omega asks you for $100, then pays you $10,000 if it predict you would have paid if it had come up tails. If it comes up tails, Omega asks you for $100, then pays you $10,000 if it predicts you would have paid if it had come up heads. In this case it was heads.

An updateless agent will get $9900 regardless of which way the coin comes up, while an updateful agent will get nothing. Note that even though you are playing against yourself, ...
Free Speech and Triskaidekaphobic Calculators: A Reply to Hubinger on the Relevance of Public Online Discussion to Existential Risk
by Zack_M_Davis — 2019-12-21T00:49:02.862Z

In response to Wei Dai's claim that a multi-post 2009 Less Wrong discussion on gender issues and offensive speech went well, MIRI researcher Evan Hubinger writes—

Do you think having that debate online was something that needed to happen for AI safety/x-risk? Do you think it benefited AI safety at all? I'm genuinely curious. My bet would be the opposite—that it caused AI safety to be more associated with political drama that helped further taint it.

Okay, but the reason you think AI safety/x-risk is important is because twenty years ago, people like Eliezer Yudkowsky and Nick Bostrom were trying to do systematically correct reasoning about the future, noticed that the alignment problem looked really important, and followed that line of reasoning where it took them—even though it probably looked "tainted" to the serious academics of the time. (The robot apocalypse is nigh? Pftt, sounds like science fiction.)

The cognitive algorithm of "Assume my current agenda is the most important thing, and then execute whatever political strategies are required to protect its social status, funding, power, un-taintedness, &c." wouldn't have led us to noticing the alignment problem, and I would be pretty surprised if it were sufficient to solve it (although that would be very convenient).

An analogy: it's actually easier to build a calculator that does correct arithmetic than it is to build a "triskaidekaphobic calculator" that does "correct arithmetic, except that it never displays the result 13", because the simplest implementation of the latter is just a calculator plus an extra conditional that puts something else on the screen when the real answer would have been 13.

If you don't actually understand how arithmetic works, but you feel intense social pressure to produce a machine that never displays the number 13, I don't think you actually succeed at building a triskaidekaphobic calculator: you're trying to solve a problem under constraints that make it impossible to solve a strictly easier problem.

Similarly, I conjecture that it's actually easier to build a rationality/alignment research community that does systematically correct reasoning, than it is to build a Catholic rationality/alignment research community that does "systematically correct reasoning, except never saying anything the Pope disagrees with." The latter is a strictly harder problem: you have to some

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Quadratic voting for the 2018 Review
by Ben Pace — 2019-12-20T22:59:07.178Z

LessWrong is currently reviewing the posts from 2018, and I'm trying to figure out how voting should happen. The new hotness that all your friends are talking about is quadratic voting, and after thinking about it for a few hours, it seems like a pretty good solution to me.

I'm writing this post primarily for people who know more about this stuff to show me where the plan will fail terribly for LW, to suggest UI improvements, or to suggest an alternative plan. If nothing serious is raised that changes my mind in the next 7 days, we'll build a straightforward UI and do it.

I've not read anything about it, so briefly, what is quadratic voting?

I'm just picking it up, so I'll write a short explanation it as I understand it, and will update this if it's confused/mistaken.

As I understand it, the key insight behind quadratic voting is that everyone can cast multiple votes, but that the marginal cost of votes is increasing, rather than staying constant.

With other voting mechanisms where cost stays constant, people are always incentivised to vote repeatedly for their favourite option. This is similar to how, under most scoring rules, people bet all their chips on the outcome they think is most likely, rather than spread their money directly proportional to their actual probability mass. You have to think carefully to design a proper scoring rule to incentivise users to write down their full epistemic state.

With quadratic voting, instead of spending all your votes on your favourite option, the more you spend on an option the more it costs to spend more on that option, and other options start looking more worthwhile. Your first vote costs 1, your second vote costs 2, your nth votes costs n. And you have a limited amount of cost you can pay, so you start having to make new comparisons about where the marginal cost should be spent.

Concretely, there are two things for a person voting in this system to keep a track of:

Votes is the total votes you make.
Cost is the total cost you pay for your votes

If you votes are

Post A: 5 votes
Post B: 8 votes
Post C: 1 vote

Then your numbers are:

Votes is 5 + 8 + 1 = 14
Cost is (1+2+3+4+5)+(1+2+3+4+5+6+7+8)+(1)=54

This is a system that not only invites voters to give a rank ordering, but to give your price for marginal votes on different posts. This information makes it much more easy to combine everyone's...
Clarifying Power-Seeking and Instrumental Convergence
by TurnTrout — 2019-12-20T19:59:32.793Z

Previously: Seeking Power is Provably Instrumentally Convergent in MDPs

Rohin Shah and Vanessa Kosoy pointed out a subtle problem with my interpretation of the power-seeking theorem from the last post. To understand the distinction, we first need to shore up some intuitions.

Correcting pre-formal intuitions about instrumental convergence

Imagine you're able to either attend college and then choose one of two careers, or attend a trade school for a third career. If you wanted, you could also attend college after trade school.

If every way of rewarding careers is equally likely, then 23 of the time, you just go to college straight away. This is true even though going to trade school increases your power (your ability to achieve goals in general) compared to just going to college. That is, Power(trade school) > Power(college), but going to college is instrumentally convergent.

We define instrumental convergence as optimal agents being more likely to take one action than another at some point in the future.

I think this captures what we really meant when we talked about instrumental convergence. Recently, however, an alignment researcher objected that instrumental convergence shouldn't depend on what state the world is in. I think the intuition was that Basic AI Drives-esque power-seeking means the agent should always seek out the powerful states, no matter their starting point.

I think this is usually true, but it isn't literally true. Sometimes states with high power are just too out-of-the-way! If you buy my formalization of power, then in what way is going to trade school "instrumentally convergent"? It isn't optimal for most goals!

This suggests that naive intuitions about instrumental convergence are subtly wrong. To figure out where optimal policies tend to go, you must condition on where they come from. In other words, the best course of action depends on where you start out.

Correcting the last post's implications

Unfortunately, the above example kills any hope of a theorem like "the agent seeks out the states in the future with the most resources / power". The nice thing about this theorem would be that we just need to know a state has more resources in order for the agent to pursue it.

Everything should add up to normalcy, though: we should still be able to make statements like "starting from a given state, the agent tends to seek out states which giv

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Polio and the controversy over randomized clinical trials
by jasoncrawford — 2019-12-20T19:49:44.991Z
Link: https://rootsofprogress.org/polio-and-the-controversy-over-randomized-clinical-trials

I’m currently reading Polio: An American Story, by David Oshinsky, and I came across a fascinating story:

In 1954, when it was time for large-scale human trials of the first polio vaccine, some researchers were against the idea of doing a properly randomized, double-blind, placebo-controlled clinical trial—including Jonas Salk, the inventor of the vaccine.

What did they want to do instead? An “observed control” trial: They would ask for volunteers (children) to get the vaccine, and then compare the rate of polio in the volunteers to the rate in their schoolmates who weren’t vaccinated. No placebo. No randomization. Not blind.

Of course, this was hopelessly confounded. In that era, the families most likely to volunteer were the more educated and affluent families (and those were actually the ones most at risk for the disease).

So why did Salk and others oppose proper randomized blind controls? The argument against a randomized trial was the urgency of protecting the nation’s children against a debilitating and deadly disease. If the vaccine worked, it would be a tragedy to withhold it from the control children. Quoting Oshinsky:

There were ethical issues as well. Were injected controls really suited to a polio trial? Was it proper, in short, to deny someone access to a potentially lifesaving vaccine in the name of statistical accuracy? Thousands of parents were going to volunteer their children to receive an injection—all of them hoping it contained the polio vaccine, not the placebo. Yet one-half of this study composed of six- to nine-year-olds, the group most vulnerable to paralytic polio, would receive a worthless liquid. Some, including Salk himself, saw this as elite science at its worst, a cynical form of Russian roulette.

Some context: the trial was massive, involving hundreds of thousands (eventually over a million) children across the country. This is not n=50 we’re talking about here. And the disease was seasonal, striking in epidemic waves every summer. So even if all the controls were properly vaccinated at the end of the trial, it would be too late for anyone who had been stricken that year.

So there was a real dilemma here. Salk himself seemed to be already convinced that the vaccine worked, and wanted it to be administered as widely as possible:

… Salk refused to budge. There must be no pla

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