Dear Jim, My understanding is that FTDNA's ICW feature just computes the "intersection of the set of matches". When they compute what matches I have ICW a cousin, say Sarah, they look at my list of matches and Sarah's list of matches and then list anyone that appears on both as an "ICW match" (no base pairs involved). I think that X-matches are anyone you share x-dna with as well as at-DNA dna. So if I share a small segment (>1cm) on the x with one of my at-DNA matches they will be listed as an X-match. ( I've found "x-matches" where the cm count is 1.7 so usually I just ignore this feature on FTDNA. ) Taryn On Tue, Dec 15, 2015 at 2:15 PM, Jim Leahy via <genealogy-dna@rootsweb.com> wrote: > How does FTDNA determine the ICW status? > > In order for FTDNA to calculate the ICW status of an individual there must > be an algorithm to evaluate the at-DNA results for that individual against > some criteria based on the at-DNA results from the base pair. Has anybody > been successful in back-engineering or divining the logic used for this > comparison? > > A related question; what does the ICW "X status" actually tell us? > > I have seen a statement implying that it means that these individuals are > "blood relatives". That would be great but seems a little too far reaching. > > Puzzled! > > Jim > > > --- > This email has been checked for viruses by Avast antivirus software. > https://www.avast.com/antivirus > > ------------------------------- > To unsubscribe from the list, please send an email to > GENEALOGY-DNA-request@rootsweb.com with the word 'unsubscribe' without > the quotes in the subject and the body of the message >

I think of them as shared matches also. If I have A and B on my list of matches and A also has B then I share B with A (ICW) Blood related it actually helpful in the sense that I am blood related to my mother and my aunt but not to my aunt's husband (assuming he is not related to me in some other way such as my mother married his brother). I am not going to actually share the same segment of DNA that my aunt's husband passed on to my cousin. Jon Masterson Wales UK, Florida US jon@scruffyduck.co.uk Gedmatch: A488362, M938817 Surnames: Cannon, Coulter, Clinton, Dryman, Lance, Mabey, Pryor, Wrixon Locations: England, Illinois, Kentucky, Texas, Utah, Virginia On 15/12/2015 14:53, Taryn Flock via wrote: > Dear Jim, > > My understanding is that FTDNA's ICW feature just computes the > "intersection of the set of matches". When they compute what matches I > have ICW a cousin, say Sarah, they look at my list of matches and Sarah's > list of matches and then list anyone that appears on both as an "ICW match" > (no base pairs involved). > > I think that X-matches are anyone you share x-dna with as well as at-DNA > dna. So if I share a small segment (>1cm) on the x with one of my at-DNA > matches they will be listed as an X-match. ( I've found "x-matches" where > the cm count is 1.7 so usually I just ignore this feature on FTDNA. ) > > Taryn > > On Tue, Dec 15, 2015 at 2:15 PM, Jim Leahy via <genealogy-dna@rootsweb.com> > wrote: > >> How does FTDNA determine the ICW status? >> >> In order for FTDNA to calculate the ICW status of an individual there must >> be an algorithm to evaluate the at-DNA results for that individual against >> some criteria based on the at-DNA results from the base pair. Has anybody >> been successful in back-engineering or divining the logic used for this >> comparison? >> >> A related question; what does the ICW "X status" actually tell us? >> >> I have seen a statement implying that it means that these individuals are >> "blood relatives". That would be great but seems a little too far reaching. >> >> Puzzled! >> >> Jim >> >> >> --- >> This email has been checked for viruses by Avast antivirus software. >> https://www.avast.com/antivirus >> >> ------------------------------- >> To unsubscribe from the list, please send an email to >> GENEALOGY-DNA-request@rootsweb.com with the word 'unsubscribe' without >> the quotes in the subject and the body of the message >> > > ------------------------------- > To unsubscribe from the list, please send an email to GENEALOGY-DNA-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message