michaelchen

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[Stats4EA] Uncertain Probabilities

What is the meaning of a higher-order probability, like a 20% chance of a 30% chance of x happening—especially if x is something like the extinction of humanity, where a frequentist interpretation doesn't make sense? I asked a question related to this https://www.lesswrong.com/posts/MApwwvQDTNdhx43cJ/how-to-quantify-uncertainty-about-a-probability-estimate

Be the Match: a volunteer list for bone marrow donation

The probability of being an HLA match might be a lot lower than 1/20,000. Say that half the potential 16,000,000 donors would renege on donating if they were called, so we actually have 8,000,000 available members. A 1 in 20,000 chance implies that the chance that a given patient has no matches would be , when in reality the chance of having a match (probably with a donor who is willing to donate?) is at least 0.01. Maybe 1 in 2 million is more reasonable?

Be the Match: a volunteer list for bone marrow donation

Some additional statistics that might be helpful for determining the counterfactual impact:

  • “1 in 300 will be selected as the best possible donor for a patient. These potential donors will have an information session with their donor center representative to learn more about the donation process. Due to changes in the patient's condition, not all donors who are selected as the best match will donate.”¹
  • “About 1 in 430 members will actually donate.”¹
  • “Because of the continuing growth and increasing ethnic diversity of the Be The Match Registry, an overwhelming percentage of patients who need an unrelated donor transplant will have a suitably matched, available donor or a CBU with an adequate cell dose on the Be The Match Registry. A 2014 study found that depending on a searching patient's ethnic background, this match likelihood is between 91-99%.”⁴
  • “about 93 percent of Caucasians will find a donor through the registry, Chell says, compared with 73 percent of Asian Americans and 67 percent of African Americans.”²
  • https://bethematch.org/transplant-basics/matching-patients-with-donors/how-does-a-patients-ethnic-background-affect-matching/ has some stats on the chance that someone of a certain ethnic background will find a matched donor (presumably of the same race). Does increased compatibility improve outcomes, or just the chance that the transplant will work out?
  • “Some 6,000 people donate bone marrow and stem cells for transplant each year through Be the Match, a Minneapolis-based registry that connects donors to ailing recipients. But there is an equal number of people who sign up to donate but decline or don’t respond when actually asked to do so. This 50-50 “commitment rate” has frustrated leaders of the National Marrow Donor Program, which operates the registry, and caused it to revamp the way it recruits donors as of next year.”³

¹ https://bethematch.org/support-the-cause/donate-bone-marrow/join-the-marrow-registry/likelihood-you-will-donate/
² https://www.washingtonpost.com/national/health-science/race-matters-when-a-patient-needs-a-stem-cell-or-marrow-transplant/2013/08/05/51abdf04-f2d9-11e2-ae43-b31dc363c3bf_story.html
³ http://www.startribune.com/being-the-match-but-not-the-donor/466167913/
https://bethematchclinical.org/transplant-therapy-and-donor-matching/donor-or-cord-blood-search-process/likelihood-of-finding-a-match/

Problems in effective altruism and what to do about them

The EA Syllabus is not an academic syllabus for the course, and "Why I'm Not a Negative Utilitarian" is not a journal-published academic paper (although it sure looks like one given the citations and structures, but is listed on Ord's website as an "unpolished idea"). Knutsson thinks that since it's directed toward the general public and not an academic audience, it's even more important that it represent all academic views fairly instead of just what the author believes. I think that it might be good to do that, but it's not unacceptable to not do that, as we can't apply academic standards to something that's not academic.

Movement Collapse Scenarios

Placing a bounty for writing criticisms casts doubt on whether those criticisms are actually sincere, or whether they're just bs-ing and overstating certain things and omitting other considerations to write those most compelling criticism they can. It's like reading a study written by someone with a conflict of interest – it's very easy to dismiss it out of hand. If CEA were to offer a financial incentive for critiques, then all critiques of CEA become less trustworthy. I think it would be more productive to encourage people to offer the most thoughtful suggestions on how to improve, even if that means scaling up certain things because they were successful, and not criticism per se.

English as a dominant language in the movement: challenges and solutions

If you're a non-native speaker, one way to improve your pronunciation is to make sure you know how the word is written in the International Phonetic Alphabet (IPA). Wiktionary is a good resource for this, and maybe also Lexico or Cambridge Dictionary. It's very difficult to correctly guess the pronunciation of an English word based on its spelling. Many non-native speakers don't do enough vowel reduction and overpronounce vowels that are actually /ə/.

Note that IPA in dictionaries is almost always phonemic and not phonetic, which means that it will not represent things like:

  • In American English, /p, t, tʃ, k/ are aspirated as [pʰ, tʰ, tʃʰ, kʰ] at the beginning of a stressed syllable, and unaspirated otherwise.† /p, t, k/ are aspirated after /s/ /t/ is often pronounced as [ɾ] between vowels (intervocalically, often even across word boundaries)‡ and as [ʔ] at the end of a syllable, except sequences like /st/ and /kt/ have [t] or [tʰ]. When the speaker is trying to speak quite formally, they may pronounce it as [tʰ], though that sounds a bit stilted to me.
  • I'm not sure about British English, but I believe that it is similar to American English except that intervocalic /t/ is pronounced [tʰ] or more casually as [ʔ], and never as [ɾ].
  • In American English, /d/ is also pronounced as [ɾ] between vowels except when beginning a stressed syllable. Again, speakers may sometimes pronounce it as [d] when trying to speak particularly formally or clearly.
  • "Vowels are [slightly] shortened when followed in a syllable by a voiceless (fortis) consonant. This is known as pre-fortis clipping. Thus in the following word pairs the first item has a shortened vowel while the second has a normal length vowel: 'right' /raɪt/ – 'ride' /raɪd/; 'face' /feɪs/ – 'phase' /feɪz/." For American English, "writer" and "rider" are both pronounced [ˈɹaɪɾɚ] but the /aɪ/ is pronounced longer in "rider", because /t/ is a voiceless consonant.
  • "In many accents of English, tense vowels undergo breaking before /l/, resulting in pronunciations like [pʰiəl] for peel, [pʰuəl] for pool, [pʰeɪəl] for pail, and [pʰoʊəl] for pole." (Wikipedia)
  • Some dictionaries for American English treat [ʌ] and [ə] as allophones of /ə/. In those dictionaries, /ə/ in stressed syllables should be pronounced [ʌ].
  • Some (even weirder) dictionaries write /e/ when they really mean /ɛ/ or /eɪ/, and /o/ when the mean /oʊ/.
  • Many speakers of American English drop the /t/ in unstressed /nt/. E.g., they might pronounce "center" as [ˈsɛnɚ] instead of [ˈsɛntʰɚ].
  • In American English, /aʊ/ is pronounced /æʊ/
  • I feel like /aɪ, eɪ, oʊ, aʊ/ are actually pronounced [ai, ei, əu, au].
  • British English is mostly non-rhotic, but inserts a /ɹ/ between vowels, even across word boundaries.
  • There's also Australian English, but I really don't understand the phonetic rules for that.
  • /ə/ is sometimes pronounced /ɪ/ in some contexts in American English; see https://en.wikipedia.org/wiki/Phonological_history_of_English_close_front_vowels#Weak_vowel_merger.

There are lots of other phonetic rules such as dark vs light /l/, but as a speaker of American English I don't really understand them.

† One exception (from Wikipedia): When the consonants in a cluster like st are analyzed as belonging to different morphemes (heteromorphemic) the stop is aspirated, but when they are analyzed as belonging to one morpheme the stop is unaspirated. For instance, distend has unaspirated [t] since it is not analyzed as two morphemes, but distaste has an aspirated middle [tʰ] because it is analyzed as dis- + taste and the word taste has an aspirated initial t. ‡ However, unstressed /tən/ is pronounced /ʔən/. "Curtain" is pronounced as [ˈkʰɚʔən], not [ˈkʰɚɾən], and "button" is pronounced [ˈbʌʔən], not [ˈbʌɾən].

Now that you know the phonetic representation, it's time to learn how to pronounce the phonemes/phones! /ɹ, ð, θ, ɑ, æ, ɪ, ɛ, ʊ, ʌ/ can be particularly difficult. I would personally focus on /ʌ/ as it's quite common and pronouncing it as /a/ sounds weirder than common approximations for other phonemes.

Also be sure to know which syllable of the word is stressed. Also note that some words are pronounced or stressed differently depending on whether it is a noun or a verb (see https://en.wikipedia.org/wiki/Initial-stress-derived_noun#List).

Honestly though, I've felt that speaking with perfect pronunciation isn't as important as having the intonation (variation in pitch of the words of a sentence) similar to a native speaker's. I think the only way to learn a native-sounding intonation is to hear English often.

English as a dominant language in the movement: challenges and solutions

What are some examples of unusual collocations? I wonder if some commonly used collocations, such as "get over", "prefer x₁ over x₂", "end up", "break the ice", and "come up with" might be more confusing to non-native speakers than expressions that are less commonly used or involve more complicated words but are more literal. I was surprised to hear that a non-native speaker friend of mine did not understand the construction "out of x₁, x₂ is the best".

English as a dominant language in the movement: challenges and solutions

I didn’t know Google Assistant was able to understand words spoken in other languages! By the way, “gratis” is an adjective or adverb that means “without charge”. I think you meant to express “free” as in “to liberate”, which would be “emancipar”, “soltar”, or “liberar”. I'm not a native Spanish speaker; I looked up the words in Wiktionary and SpanishDict to double-check their definitions.

ACE Call for External Reviewers

Why does the form have Email address, Name, then Email address (again)?

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