Ann, It's close. As I understand the Matrix and ICW tools at FTDNA, neither guarantee Triangulation. Sometimes the folks ICW and the Matrix are not on the same segment; although most of the time, they are. The Matrix does not check the DNA segment (someone correct me if this is incorrect). If -most of the time- is good enough for you, OK. If not you need to request those Matches to confirm on the Chromosome Browser that they indeed match each other on the segment in question. If they call up each other, it should look like a slice of lasagna on Chr 5. Jim Bartlett On 12/18/13, AGilchrest@aol.com wrote: Jim, On Chr. 5 I have a group of 6 people including "Miss Smith" who all have overlapping segments & match each other with father in the Matrix on FTDNA. I am assuming that this is the triangulation you are referring to. Ann In a message dated 17-Dec-13 10:44:57 US Mountain Standard Time, [1]jim4bartletts@verizon.net writes: Ann, I agree with your assessment - both parents probably have a Common Ancestor with Miss Smith - on different chromosomes (it could be the same answer, if the segments were on the same chromosome, even if they appeared to overlap on the same chromosome - it's the random luck of the draw) You have reinforcing evidence for the match on Chr 2. You do not have strong reinforcing evidence on Chr 5 - your very small segments are usually IBS, so the match your Dad has would be a little iffy for me. I'd be looking for Triangulation with other Matches on this segment - through your testing company, and at GEDmatch. If you get some to Triangulate, his segment is firmed up. Your little segments are still in the random area. I'd be looking for larger matches in this area. Sooner or later you will probably get a larger match covering this area of Chr 5, and you can then see how your Dad fits in. It's very difficult to make a guarantee without Triangulation and other reinforcing data. Jim Bartlett On 12/17/13, [2]AGilchrest@aol.com wrote: Hello, My parents are not related. My father has a match with Miss. Smith on chromosome 5 5 108992806 120529341 11.03 2800 5 120909339 123937399 3.79 700 My chromosome 5 data are as follows: 5 113100374 115158825 2.37 500 5 117726378 120529341 2.56 600 5 137555847 110861658 2.86 600 My mother matches Miss Smith on chromosome 2, 2 212452431 220488105 10.18 2100 My chromosome 2, 2 212452431 220488105 10.18 2100 My mother's sister and a nephew also match Miss Smith on chromosome 2. Based on the above. It appears that Miss Smith shares a common ancestor with both of my parents. Is this a valid conclusion? I am also wondering if my chromosome 5 data is part of the segment that my father has? Thank you, Ann Gilchrest References 1. mailto:jim4bartletts@verizon.net 2. mailto:AGilchrest@aol.com