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Comment author: Anders_H 18 January 2017 01:23:22AM *  2 points [-]

I skimmed this paper and plan to read it in more detail tomorrow. My first thought is that it is fundamentally confused. I believe the confusion comes from the fact that the word "prediction" is used with two separate meanings: Are you interested in predicting Y given an observed value of X (Pr[Y | X=x]), or are you interested in predicting Y given an intervention on X (i.e. Pr[Y|do(X=x)]).

The first of these may be useful for certain purposes. but If you intend to use the research for decision making and optimization (i.e. you want to intervene to set the value of X , in order to optimize Y), then you really need the second type of predictive ability, in which case you need to extract causal information from the data. This is only possible if you have a randomized trial, or if you have a correct causal model.

You can use the word "prediction" to refer to the second type of research objective, but this is not the kind of prediction that machine learning algorithms are designed to do.

In the conclusions, the authors write:

"By contrast, a minority of statisticians (and most machine learning researchers) belong to the “algorithmic modeling culture,” in which the data are assumed to be the result of some unknown and possibly unknowable process, and the primary goal is to find an algorithm that results in the same outputs as this process given the same inputs. "

The definition of "algorithmic modelling culture" is somewhat circular, as it just moves the ambiguity surrounding "prediction" to the word "input". If by "input" they mean that the algorithm observes the value of an independent variable and makes a prediction for the dependent variable, then you are talking about a true prediction model, which may be useful for certain purposes (diagnosis, prognosis, etc) but which is unusable if you are interested in optimizing the outcome.

If you instead claim that the "input" can also include observations about interventions on a variable, then your predictions will certainly fail unless the algorithm was trained in a dataset where someone actually intervened on X (i.e. someone did a randomized controlled trial), or unless you have a correct causal model.

Machine learning algorithms are not magic, they do not solve the problem of confounding unless they have a correct causal model. The fact that these algorithms are good at predicting stuff in observational datasets does not tell you anything useful for the purposes of deciding what the optimal value of the independent variable is.

In general, this paper is a very good example to illustrate why I keep insisting that machine learning people need to urgently read up on Pearl, Robins or Van der Laan. The field is in danger of falling into the same failure mode as epidemiology, i.e. essentially ignoring the problem of confounding. In the case of machine learning, this may be more insidious because the research is dressed up in fancy math and therefore looks superficially more impressive.

Comment author: Kaj_Sotala 13 February 2017 12:26:44PM 0 points [-]

Not entirely sure I understand you; I read the paper mostly as pointing out that current psych methodology tends to overfit, and that psychologists don't even know what overfitting means. This is true regardless of which type of prediction we're talking about.

[Link] Against willpower as a scientific or otherwise useful concept (Nautilus Magazine)

0 Kaj_Sotala 04 February 2017 10:11PM
Comment author: Kaj_Sotala 22 January 2017 11:44:05AM 4 points [-]

Do you feel the "link post ugh"?

Submitting...

[Link] Choosing prediction over explanation in psychology: Lessons from machine learning

1 Kaj_Sotala 17 January 2017 09:23PM

[Link] Disjunctive AI scenarios: Individual or collective takeoff?

3 Kaj_Sotala 11 January 2017 03:43PM
Comment author: cousin_it 28 December 2016 08:54:25PM *  19 points [-]

I've found a nice hack that may help others: practice starting and stopping to do stuff, rather than just doing or not doing stuff.

Example 1: if you want to practice drawing, instead of forcing yourself into a long drawing session, repeat the action "drop whatever else you're doing and start drawing practice" five times within one day. Then it'll be easier the next day.

Example 2: if you want to surf the internet less, instead of forcing yourself to stay away from the computer for a long time, repeat the action "stop surfing and relax for a minute" five times within one day. Then it'll be easier the next day.

I don't know if this stuff works, but it gives me a cool feeling of being in control :-)

Comment author: Kaj_Sotala 30 December 2016 01:50:36PM 3 points [-]

Based on what I know of habit formation and the principles of deliberate practice, this should work.

A friend also commented that it worked for her when she wanted to start exercising more regularly.

Comment author: Kaj_Sotala 29 December 2016 06:19:56PM 14 points [-]

It's my understanding that in a democracy, the criteria for how various groups of people are treated isn't so much "are these people economically useful for the state", but rather "how much voting power do these people have and use" (the democracy parts of The Rulers for Rulers are relevant here). For instance, as the linked video notes, countries where the vote of the farming block swings elections tend to have large farming subsidies, even though this pretty much means that the farmers need the state financially and not the other way around.

It seems plausible to me that UBI could even make its recipients more politically influential: I used to have some involvement with Finnish politics, and heard that the various political parties rely a lot on pensioners as their volunteers, since pensioners have a lot of spare time that they can use on politics. This would suggest that interventions such as the UBI that may give its beneficiaries more free time, increase the chances of those beneficiaries participating in the political system and thus being taken more into account in decision-making.

Comment author: Bobertron 20 December 2016 11:05:47PM 2 points [-]

Interesting article. Here is the problem I have: In the first example, "spelling ocean correctly" and "I'll be a successful writer" clearly have nothing to do with each other, so they shouldn't be in a bucket together and the kid is just being stupid. At least on first glance, that's totally different from Carol's situation. I'm tempted to say that "I should not try full force on the startup" and "there is a fatal flaw in the startup" should be in a bucket, because I believe "if there is a fatal flaw in the startup, I should not try it". As long as I believe that, how can I separate these two and not flinch?

Do you think one should allow oneself to be less consistent in order to become more accurate? Suppose you are a smoker and you don't want to look into the health risks of smoking, because you don't want to quit. I think you should allow yourself in some situations to both believe "I should not smoke because it is bad for my health" and to continue smoking, because then you'll flinch less. But I'm fuzzy on when. If you completely give up on having your actions be determined by your believes about what you should do, that seems obviously crazy and there won't be any reason to look into the health risks of smoking anyway.

Maybe you should model yourself as two people. One person is rationality. It's responsible for determining what to believe and what to do. The other person is the one that queries rationality and acts on it's recommendations. Since rationality is a consequentialis with integrity it might not recommend to quit smoking, because then the other person will stop acting on it's advice and stop giving it queries.

Comment author: Kaj_Sotala 22 December 2016 06:32:59PM *  0 points [-]

In the first example, "spelling ocean correctly" and "I'll be a successful writer" clearly have nothing to do with each other,

If you think that successful writers are talented, and that talent means fewer misspellings, then misspelling things is evidence of you not going to be a successful writer. (No, I don't think this is a very plausible model, but it's one that I'd imagine could be plausible to a kid with a fixed mindset and who didn't yet know what really distinguishes good writers from the bad.)

Comment author: Elo 17 December 2016 08:38:56AM 0 points [-]

As a very shitty theory; the results might be able to be explained by frequency of exercise associated with sauna use. i.e. if I go in the sauna every time I gym and I gym 7 days a week instead of 1 day a week I can presume that means I am healthier or am more likely to be healthier.

Previous results from the KIHD study have shown that frequent sauna bathing also significantly reduces the risk of sudden cardiac death, the risk of death due to coronary artery disease and other cardiac events, as well as overall mortality. According to Professor Jari Laukkanen, the study leader, sauna bathing may protect both the heart and memory to some extent via similar, still poorly known mechanisms. “However, it is known that cardiovascular health affects the brain as well. The sense of well-being and relaxation experienced during sauna bathing may also play a role.”

As I would expect with general health. I barely know anyone who uses a sauna, let alone anyone who uses one 7 days a week. Mainly due to them mostly existing in conjunction with health infrastructure like gyms and swimming pools.

Comment author: Kaj_Sotala 17 December 2016 05:36:08PM *  4 points [-]

Note that the study is from Finland, where sauna-going is not particularly associated with exercise: people just go into the sauna for its own sake. There are saunas in conjunction of gyms, yes, but e.g. apartment buildings often have their own dedicated saunas that the tenants can reserve for their own use. (Somebody having a single one-hour sauna shift per week is typical.)

That said, there are probably other confounders in that e.g. people who can use a sauna seven times a week are a lot more likely to have a sauna of their own, so live in their own house rather than an apartment, among other things.

Comment author: Kaj_Sotala 17 December 2016 05:31:42PM 4 points [-]

Could you elaborate on the developmental tasks, at least the bolded ones? I think I get their rough contents, but their descriptions are short enough that it might just be an illusion of understanding.

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