Different DNA results on Ancestry and My Heritage??

[Gadget]

I have read that Ancestry seeks to eliminate the ‘background noise’ ie the kind of matching that occurs within a general population.

This would only be the case if the downloaded file from Ancestry included the 'noise' 

[Galium]

Speculating here; I don't know either way, but I think the raw data that you transfer from Ancestry to another site is your whole profile, not just the part that Ancestry decides to use in its calculations. 

So thinking of your DNA test result as being like a  book that Ancestry takes a set of quotes from to work with, and ignores the rest, what you send to MH is a copy of the whole book, which it can quote from as it chooses.

[Gadget]

Like all the scatter  points on a regression chart 

[squawki11]

Ancestry's Timber algorithm probably accounts for the differences. Uploading to gedmatch is useful, eliminate hard breaks and look at the size and number of segments. If you have tested rather than uploaded to MH, gedmatch will show the differences between the sets of raw data. Just a suggestion for those more deeply interested...

[Gadget]

That's fine but only if the match is on Gedmatch too.

[squawki11]

Obviously. But for the purpose of illustrating the differences, I had, perhaps mistake!y, assumed that you might have tested at both ancestry and MH, or even elsewhere?

[Gadget]

I have but many of those who match have not.

The most important thing is to link up to a common ancestor and that can often be done without a full inspection using a chromosome browser, etc.  I find that such tools are often used to the detriment of good solid  genealogical research and can often be used as displacement activity.

[squawki11]

I don't disagree with your rationale. Not everyone wishes or needs chromosome details. The question posed appeared to be regarding the different cM/segments between matches one might have on ancestry compared to the same matches on MH. It's not clear how else they might be compared other than by using gedmatch. It just happens to be the case that an ancestry match will almost always show a greater cM if that match is also on gedmatch. You may be lucky enough to have access to more than your own raw data and try the above for yourself or pose the question elsewhere?

[Gadget]

Thank you for your interest. I'm puzzled by your replies - especially suggesting that I

pose the question elsewhere?

which appears rather arrogant on your part.

I asked about the different results on Ancestry and My Heritage. The  most logical answer was that Ancestry used post-processing methods to get rid of background  'noise' but My Heritage takes the data uploaded from Ancestry and uses a different technique or leaves the 'noise' as is. I'm quite happy to accept this.

In the cases discovered, we have identified the particular family line that the connection occurs in. I was just interested in why MH had a higher shared DNA than Ancestry.

Gadget