But hopefully, you will not be satisfied to just make a general statement here when we do have these glitches.
但是希望,大家不会仅,仅因为大致符合就满意了,毕竟还有些小偏差。
And also in a row three, yeah, we're generally increasing, there's some glitches here, but the general trend holds true.
另外对于第三行,也对,我们大体上是在升高的,只是这里有些小偏差,但是总体规律是正确的。
So the survivorship bias and the backfill bias would be much,much more of a problem in the hedge fund world.
所以生存偏差和回填偏差,会是对冲基金领域里一个相当重大的问题
So suppose that we consider a deviation in which, and again I've forgotten your name in which Stacy stands as well.
假设我们考虑一种偏差的情况下,我又忘了你的名字了,斯泰西也参选了
7% 77% is class average and the standard deviation was 17% so you can see where things lie. 50% is a pass.
7是平均水平,标准偏差是%,这就是事情所在,50%就及格。
All right, we were down here, and I was saying, let's try a larger, introduce a bias.
好了,我们在这儿,我刚才说,让我们试试一个比较大的偏差值。
But anyway, college students, not here, show systematic biases of incorrect physical intuitions.
但不管怎样,大学生,不算这里的,在错误的物理直觉方面存在系统性偏差
One way of investigating this is-- to get around the selection bias-- is to try to look at all countries.
为了避免选择性偏差,研究方法之一是,研究所有的国家
So that explains one of our glitches here, but we have another glitch, and that second glitch comes between nitrogen and oxygen.
那么我们的第一种小偏差已经解释清楚了,但是我们还有另外一种,它在氮和氧之间发生。
And then I could also do a Gaussian one here, with the mean of and the standard deviation of volatility divided by 2.
然后我在这里再写一个高斯分布的函数,它的浮动值的平均值和,标准偏差值都除了2。
Looking at this particular group, he estimated survivorship bias to be 4.4% per year and backfill bias to be 7.3% per year.
分析这个特定的样本,他估算其生存偏差每年达到4.4%,回填偏差每年达到7.3%
Then if you adjust for survivorship bias, you end up concluding that the deficit wasn't .3% but the deficit was actually 2%.
那么如果你算上生存偏差,你会发现,缺口不是0.3%,事实上是2%
So, taking just the outermost electron might give us some false readings.
所以只取离中心最远的那个电子的电离能,可能会使我们的认识发生偏差。
You've got survivorship bias taking out bad records and then you've got backfill bias adding good records.
生存偏差去掉了那些糟糕的记录,回填误差又加入了一些好的记录
One standard deviation happens one draw out of three, two standard deviations one out of twenty, three standard deviations is one out of one hundred.
落在一个标准偏差之外的概率是1/3,两个标准差之外的概率是1/20,三个标准差之外是百分之一
It could be normal, everything, that would be a Gaussian, where if you recall there was a mean, and a standard deviation, and most values were going to be close to the mean.
可能是正态分布,也就是高斯分布,只要有平均值和标准偏差值,你就可以进行调用,大部分的值都是集中在平均值附近的。
So, let's consider specifically where these glitches are taking place.
那么让我们来具体地想一想,这些小偏差发生在哪里。
So there's three possible types of deviation here that we need to check.
这有三种可能的偏差,需要我们验证
Now,more than 130 managers failed because, in addition to survivorship bias, there's something called backfill bias.
其实失败的经理人超过130位,因为除了生存偏差之外,还有称为回填偏差的影响
Let's go back to where, a simpler bias here.
我们回到这里,一个简单的偏差值。
Especially if there is a small standard deviation.
特别是当标准偏差值很小的情况。
The title of the book, Stocks for the Long Run-- stocks always outperform other investments for the long run and he says it's not due to selection bias.
书名是为《股市长线法宝》,长期投资中股票总是比其他资产有更高的收益,他认为他在研究中排除了选择性偏差
So,we're talking about a group of funds that in aggregate probably produced somewhere in the low teens returns and he's got 11.7% per year combined survivorship bias and backfill bias.
因此我们说这组基金总体上,大概产生了略高于10%的收益率,他算出的数字是每年11.7%,结合了生存偏差和回填偏差
So, let's take a look at one of these rows in more detail to think about why this might be happening, and it turns out the reason that these glitches occur are because the sub shell structure predominates in certain instances, and that's where these glitches take place.
那么,让我们仔细地看一看其中一行,想一想为什么会这样,结果是这些小偏差的出现,是因为在一定情况下,亚壳层结构会产生重要影响,这正发生在小偏差出现的地方。
Because the U.S. is an arguably very successful country, so we have, potentially, a bias in--it's called a selection bias.
因为毫无疑问美国是个很成功的国家,因此我们的潜意识中,存在选择性偏差
So the other possible deviation we have to consider, is a deviation of the form of one of these guys dropping out.
那么另外一个我们必须要考虑的偏差,是她们俩有一个人退出选举
So,the combination of survivorship bias and backfill bias for that one year made 4.3 percentage points difference.
因此在生存偏差和回填偏差的共同作用下,造成了两个收益率之间4.3%的差值
We could also feel pretty comfortable that that's probably way too high a bias, right?
另外因为这个偏差值很高,所以结果才这么高?
What this means in the insurance context is that if you offer insurance policies you will tend to attract people who are higher risk.
保险中选择性偏差的意思是,如果你提供某个险种,吸引的是承受该险种风险较大的人群
I missed by a mile, which is a problem in drawing my lines, but never mind.
我画得偏差太大了,应该是线的问题,但这无所谓了
应用推荐