Lindsey My approach was to triangulate virtually all my Matches over 7cM. That covered just over 85% of my DNA. Then I dropped down and added segments 5-7cM - probably more than 90% did not triangulate with existing TGs which covered the same area. This mean they were IBS/false. The IBD small segments did help some TGs, and created just a few more - most fell within existing TGs - no help with coverage, but some were helpful confirming CAs. Starting over, I'd use 10cM to start - to build the initial set of TGs. Then add the 7-10cM segments; then add the 5-7cM shared segments. Build a strong base, then see what fits. I am not caught up with contacting every Match in each TG, so I'm not ready to try any segments below 5cM. They would get very boring - usually failing the triangulation process; and the CAs would probably be very distant. In a special interest TG, however, I might reconsider. Jim - www.segmentology.org > On Dec 3, 2015, at 8:39 AM, Lindsey Britton via <genealogy-dna@rootsweb.com> wrote: > > > Some are under 5cm. I don't know whether smaller segments are common among European ancestors except perhaps those I found on the x chromosome which we appeared to share with dozens of other people who seemed to be related on more that one line. > > No answer yet to the first triangulation match I notified. So far I've done better taking a genealogical approach based on the nature of the match, matches in common, and surname lists. > > Lindsey > > > > > > > > -----Original Message----- > From: Andreas West <ahnen@awest.de> > To: Lindsey Britton <lplantagenet@aol.com>; genealogy-dna <genealogy-dna@rootsweb.com> > Sent: Wed, Dec 2, 2015 10:41 pm > Subject: Re: [DNA] Small segment matches when the common ancestors are known > > Not too much but you still have to set reasonable minimum criteria in SNP and genetic distance. > > Otherwise the same rules of triangulation apply, just be aware that there are very small segments like the Western Haplogroup Ancestral Segment on CHR 2 that everyone with European background seems to have. > > Andreas > >> On 3 Dec 2015, at 05:31, Lindsey Britton via <genealogy-dna@rootsweb.com> wrote: >> >> >> Is the approach different for segments less than 7cm when the relationship (for example 4th cousin once removed or 5th cousin once removed) and common ancestors are already known? >> >> Lindsey >>