> Has anyone built a standalone Mac app using JQt? Please see http://www.jsoftware.com/jwiki/Guides/J8%20Standalone
On 25 February 2015 at 06:09, Ian Clark <[email protected]> wrote: > @Henry -- thanks for your comments. Great! > > IMO this is just the sort of discussion I would like to see aired in > public. Though maybe do the more philosophical stuff in Chat? > Ideally I would like a summary of the J community's findings > documented on a Jwiki page for wider consumption. > > Further comments in-line… > > > On Wed, Feb 25, 2015 at 4:27 AM, Henry Rich <[email protected]> wrote: > > We should take this off-group, but I'm replying in public because if I'm > > wrong I would like to be corrected (and I'm only an amateur > statistician): > > That's exactly why I'm appealing to the forum too. > …To the annoyance of Real Statisticians, no doubt, because this must > be elementary stuff to them. > But Wikipedia -- which you'd expect to give simple answers to simple > questions which laypeople want to ask and need to ask -- approaches > the whole issue like a cat circling a bowl of hot porridge. > …If you're a layperson, just try working out how to score the "Lady > Tasting Tea" experiment from these pages… > https://en.wikipedia.org/wiki/Binomial_test > https://en.wikipedia.org/wiki/Binomial_distribution > https://en.wikipedia.org/wiki/Bernoulli_distribution > https://en.wikipedia.org/wiki/Bernoulli_trial > https://en.wikipedia.org/wiki/Bernoulli_process > > As a Human Factors *engineer* -- I've been a professional *user* of > hypothesis-testing but an amateur Statistician. > …Or should that be Probabilist? Or even Epistemologist? > > Plus… now I'm retired, I'm getting rusty. > > Plus… I can't find precise enough documentation of JAL verb: binomialprob. > Like… what's the semantics of the 3rd entry of (y) (styled "minimum > number of successes (s)") when y has only 3 entries? Can it be called > "minimum" any more? What I've concluded, after a bit of RTFC plus a > few idiot tests, is: > > (binomialprob 0.5,N,s) -: (binomialprob 0.5,N,s,N) > > Plus… has this doggie got 2 tails or just 1?? > > > > I think you are calling binomialprob correctly but I have some > objections to > > your use of the result. > > > > 1. I think your rejectH0 should use 1 - -: CONFIDENCE instead of > > 1-CONFIDENCE. > > > > The question is, "How likely is a result as weird as I am seeing, > assuming > > H0?" You should not bias "weird" by assuming that weird results will be > > correct guesses - they could just as likely be incorrect guesses. To > ensure > > that you reject 95% of the purely-chance deviations of a certain size, > that > > 95% should be centered around the mean, not loaded toward one side. > > The "1-tail-or-2?" question -- or so I thought at first. > But it's deeper than that. It's much more serious. Serious enough to > be the key issue for me. > Which is precisely why I want to be *sure*. Sure enough to argue my > case to a determined layperson. Not merely make an inspired guess, as > most people would in an industrial situation (…knowing no one else > knows enough statistics to dare to challenge you!) > > What I understand @Henry to be saying is: should the 5% area under the > binomial distribution curve, which sets the pass/fail threshold, be > shared equally between both tails? Even if one tail happens to be in > fairyland? > > What I mean by that last remark is… > If The Lady Tasting Tea (TLTT) gets every trial *wrong*, then she's > *not* a monkey flipping a fair coin. It's a very biased coin! > She is sending a strong signal that she can be depended upon (…with X% > confidence) to make the wrong decision. > But I don't want to credit her this as evidence to support her claim > she can tell the difference (…at least, not tell it correctly). > This is what makes TLTT different from detecting a biased coin by > repeated tosses. > > What's to do? > > > > are there really people who think optical might be better than USB?? > > Oh-ho-ho! -- yes, they can still be found. > Hi-Fi buffs have not become extinct, and the (undead?) audio industry > still lives off their lifeblood. > > > > This is digital communication, no? 44K samples/sec, 2 channels, 20 > bits/sample, > > needs 2Mb/sec max out of 480Mb/sec rated USB speed... how could that not > be > > enough? > > My interlocutor claims it's like the group was there, in his front > room, playing "just for him". > Now this guy is an intelligent chap, a developer of digital musical > instruments and a sound engineer as well as being an accomplished > musician. He sends me two MP3s (…yes, lossy MP3s!) to support his > claim. I drop these into Audacity and inspect the waveform at very > fine detail and I cannot for the life of me detect any difference. > So I know, as sure as God made little Apples, that I'm not going to > *hear* any difference. > But I've got lo-fi ears. In fact I'm half-deaf. Most of what I hear I > imagine. Mostly I get it right with people (I think…) But I don't know > what subliminal cues I'm using to do so. It's the "clever Hans" > effect. > > Maybe there are people who *can* tell the difference? But from my > pondering the figures, like you have, plus eyeballing the waveforms, > we're talking about magical superpowers here. > > > > It was ever thus... when I last looked at this sort of thing, 20 years > back, > > the debate was whether big fat expensive cables would make a difference. > > Bob Pease, a respected analog engineer, pointed out that it was > impossible, > > and James Randi had a bet that no one could discern $7000 cables from > > ordinary speaker wire, but still the non-EEs have their superstitions...] > > That's around the time my son was spending all his pocket-money on big > fat speaker cables and gold-plated jack-plugs. > Now he's teaching a Theory of Knowledge course (…yes, Epistemology!) > at a school in Hong Kong. He is greedy to get his hands on my little > program, and dispel a few lingering superstitions masquerading as > received wisdom about science. > > I want to package it up and send it to him, but I don't want to ask > him to install J on his Mac because not only will he grouse like heck > about fairy software but it will discourage him sharing the app with > his colleages, who share his sentiments. > > I know how to package up a standalone Mac app in J602, but J602 and my > packaged apps no longer work out-of-the-box on the Mac under Yosemite > (it's to do with 32-bit Java). Has anyone built a standalone Mac app > using JQt? If so I'd dearly love to see a monkey-see monkey-do page on > Jwiki. I'll write one myself, but it'll be a year before I can get > round to it. > > > > 2. Why 95%? I would fear that someone who is thinking about optical > cable > > would rest uneasy with a 5-10% chance that they have not spent enough on > > quality audio. Why not simply report, "A monkey with a coin to toss > would > > do as well as you y% of the time. Most researchers accept results as > > significant only if the monkey would do as well less than 5% of the time. > > Take more samples if you want less uncertainty." > > 95% is just for the sake of argument. 99% is there as an option. IMO > more options are neither necessary nor advisable. > The number of trials can be varied too. I'd like to offer 10 or 20 > trials. But 20 gets tedious, so I'm offering the option to give up > when you're bored and score the number you've done. > (This is an app for discretionary users -- we're not paying our > subjects $10 a session.) > > Anything under 7 trials fails to reject H0 however many successes. But > that's dependent on the value of CONFIDENCE and how it's to be > applied. But only to make a difference of 1 or maybe 2 trials. > I'm finding in practice that with such a low number of trials as 10, > anything short of 100% correct is statistical hairsplitting when it > comes to rejecting H0. With 20 trials there's more leeway: you're > allowed to get 3 or 4 wrong before the app rubbishes you. > > As for your wording: it's theoretically sound, but a trifle insulting. > Performing musicians have sizeable egos and wouldn't like to be rated > along with performing monkeys. :-) > > Ian > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
