How large a sample size is needed to we could get accurate results for a population?

**Peterski** · 08-20-2017, 12:37 PM

Originally Posted by Laberia

I have read in a study that they tested 26 Albanians, one for every region. Can we conseder the result of this study acceptable?

In K36 Oracle, Albanian sample size is very large, a few hundred IIRC.

**Peterski** · 08-20-2017, 12:40 PM

Originally Posted by Magnolia

There are mathematical methods for the sample size determination (it is not only about the sample size but all regions have to be in the correct proportions represented. Samples has to be taken randomly. Etc.

Only if these conditions are fulfilled, than one can make credible conclusions. Otherwise - zero value. The aim - manipulate people, or eg to deal with own complexes.

I'm using samples from Harvard's Human Origins Dataset, including Lusatian Sorbs, Poznan Poles, Lublin Poles, Sachsen Germans.

Other samples are also found randomly, via GEDmatch:

https://www.theapricity.com/forum/sh...=1#post4368219

https://www.theapricity.com/forum/sh...=1#post4542509

**~~Laberia~~** · 08-20-2017, 12:47 PM

Originally Posted by Litvin

In K36 Oracle, Albanian sample size is very large, a few hundred IIRC.

Let simplify a litle bitt our discussion.
We have a region, region N. This region is inhabitated by 1.000.000 people. You are a team leader of a group of geneticists and your duty is to determine the haplogroups present in the population of region N and the percentages for every haplogroup. First way is testing the inhabitants one by one but of course this is not possible for the moment, maybe in the future. So, you have to start to select some people to test. How many people you have to test from the inhabitants of the region N and how they are selected in order to have an acceptable result? I mean the minimum of samples.

**Magnolia** · 08-20-2017, 12:55 PM

The main issue with these samples is that these are taken from people who were tested from their own will. They wanted to be tested for a reason (eg there is a family story their grand-grandfather was a Jew - they want to confirm it by a test...).

Anyway if there is somthing written on internet - no methology is mentioned, no information about the size sample, etc., even the terminology is not accurante - everyone with brain should know it is crap.

**Peterski** · 08-20-2017, 12:56 PM

Originally Posted by Laberia

Let simplify a litle bitt our discussion.
We have a region, region N. This region is inhabitated by 1.000.000 people. You are a team leader of a group of geneticists and your duty is to determine the haplogroups present in the population of region N and the percentages for every haplogroup. First way is testing the inhabitants one by one but of course this is not possible for the moment, maybe in the future. So, you have to start to select some people to test. How many people you have to test from the inhabitants of the region N and how they are selected in order to have an acceptable result? I mean the minimum of samples.

For haplogroups, the more the better. So I would want at least 150 people from region N.

But autosomal DNA is something different. For this purpose 50 people would be enough.

**Magnolia** · 08-20-2017, 01:03 PM

lol. It is funny to see a person who has no clue that these methods exist to say how large samples should be...

**~~Laberia~~** · 08-20-2017, 01:05 PM

Originally Posted by Litvin

For haplogroups, the more the better. So I would want at least 150 people from region N.

But autosomal DNA is something different. For this purpose 50 people would be enough.

Where we can read this? Is this written in some texts or this is only your personal opinion?
And how this persons have to be selected, russian roulet or there is an methodology taking in consideration the history of the region, etc?

**~~Rethel~~** · 08-20-2017, 01:13 PM

Originally Posted by Magnolia

should know it is crap.

Maybe not crap, but we do not have something better.

Tests should be make the same way, as any statistic is made.
Should be divived on population size by age, county, province, proportionaly to the density aso.

Obviously it is not. so the results of %% of hgs, are +/- with big margines of error.

Austosomal - could be a crap, especially, that tested groups are much smaller than
in the case of hg, much more coincidental, and as we can see on this forum, different
analysys give different results. Litwin once is a Slovakian, another time he is a Masovian,
after another method he is a Greatpole. And btw, autosomal analysys were statrted as a
crap commercial testing for migrants in America, who did not know were they are from.
They are happy like children when you tell them that they are 10% Zulu, 1% Massai 5% Finn,
15% Ainu, 9% Navajo - but it has no practical relevance, and tells nothing about someone's
provenance - if it is trustfull test at all. Even if is, then is worthless anyway in personal case.

**Peterski** · 08-20-2017, 01:14 PM

Magnolia called me "amateur geneticist".

But I'm employed by a DNA testing company, and officially a genetics professional:

And who are you Magnolia? A toilet cleaner?

**Magnolia** · 08-20-2017, 01:20 PM

lol You are a brigadier with no education in genetics, mathematics, statistics, not even in history. Unlike you I know exactly what I'm speaking about in this thread ; ). Btw. It says a lot about that company that they have an universal contract for everyone.

And dont be afraid Poles are very good in toilet cleaning, we dont have to do that, nobody in Europe have to. It is your specialization. Everybody knows that.