First of all, the percentages given are simply the likelihood of having a common ancestor within a certain number of generations but the common ancestor predictor does not show exactly when a common ancestor will be found. If you have an 80% chance of having a common ancestor with a dna match in 8 generations back, a common ancestor could be found in a lesser or greater number of generations. In this example the 80% means that 80 times out of 100 that you will find a common ancestor within the 8 generations and that find could have occurred in any generation from 2nd to 8th. Put another way it means there will be a common ancestor found some generation within 8 generations 80% of the time. The opportunity to refine your results is for those matches for whom you have NOT found a common ancestor and gives you a chance to put in the number of generations you know there is not a common ancestor and the results will be refined to show you more precisely how many generations back that common ancestor will likely be found. It has no value for those matches with whom you know you have a common ancestor. "What exactly does this mean: These results can be refined if their paper trail indicates that no common ancestor between Norman Kincaide and Treasa Brookman could have lived in a certain number of generations." This simply means that the percentages of having a common ancestor will be mathematically refined if you know you do not have a common ancestor in so many generations with a match and input that number of generations. The refinement results will show a larger number of generations to find a common ancestor so be sure to watch for the change in number of generations in the refined results as well as the percentages. "Then there is: However, if you have the information, please enter in the box and click on the recalculate button. (Does this mean that if you are certain that Norman Kincaide & Treasa Brookman had a common ancestor 8 generations ago you enter that number in the box)" I believe the answer to this question is no. If you know you have a common ancestor there is no need to use the refinement process since you already know the common ancestor. "So my main question is: Does knowing that paper trail information increase the percentage of having a common ancestor or not?" The paper trail information should decrease the percentage of having a common ancestor within the same number of generations however remember Family Tree DNA changes the number of generations in the refinement instead of lowering the percentage for the same number of generations. I wish they would change the percentage and leave the number of generations the same since it would make comparison much easier and less confusing! Here is an example from my personal situation. In looking at the FTDNA probability information for my # 1427 closest dna match for 67 markers, James Elliott Kincaid, # 2563, FTDNA shows 85.95% likelihood of finding a common ancestor within 8 generations before doing a refinement. Since our documentation shows there cannot be a common ancestor within 7 generations we put 7 into the box and hit recalculate and see that the refinement shows a 77.76% of having a common ancestor is for the period of 7 up to 11 generations. It also shows that for 15 generations, the percent is 95.98%. This does not tell me which generation to expect to find a common ancestor with 2563, just the odds or likelihood of doing so within a certain number of generations. In my and Jim's case I personally believe we will find a common ancestor within 2 or 3 generations beyond each of our most distant ancestors that are known in early to mid 1700's. I should note that the refinement opportunity for each match will be for the highest number of markers dna test used for both participants so in my example, I cannot use the 37 marker results for anything other than the 4, 8, 12 & 16 generation percentages and if I want to refine my percentages I have to use the 67 marker results. The more markers a participant has been tested for the better the mathematical probability will be more meaningful. Yours aye, Don W. Kincaid Kincaid Surname DNA Administrator Team donwkincaid@cox.net 254 631-5684 ----- Original Message ----- From: Norman Kincaide To: kincaid@rootsweb.com Sent: Tuesday, September 23, 2008 6:40 PM Subject: [KINCAID] common ancestor question Does anyone know what this means? It's from the Family Tree DNA website and I have read it over several times. Refine your results with paper trail input The above numbers are based exclusively on the comparison of their Y-DNA results, which show 2 mismatches. However, these results can be refined if their paper trail indicates that no common ancestor between Norman Kincaide and Treasa Brookman could have lived in a certain number of past generations. If you don't know this information for a fact, do not change the "1" in the box in the next paragraph. However, if you have the information, please enter in the box and click on the recalculate button. What exactly does this mean: These results can be refined if their paper trail indicates that no common ancestor between Norman Kincaide and Treasa Brookman could have lived in a certain number of generations. And then: If you don't know this information for a fact (does this mean that the paper trail information does not show a common ancestor) do not change the "1" in the box. Then there is: However, if you have the information, please enter in the box and click on the recalculate button. (Does this mean that if you are certain that Norman Kincaide & Treasa Brookman had a common ancestor 8 generations ago you enter that number in the box) The paper trail indicates that my John Kincaid who married Elizabeth Smith and her William Kincaid who married Elizabeth Glenn were the sons of John Kinkead who married Margaret Miles and died in Union Township, Erie County, PA in 1822. So my main question is: Does knowing that paper trail information increase the percentage of having a common ancestor or not? Sincerely Norman Kincaide To see the Kincaid of all spellings DNA chart in Excel: http://freepages.genealogy.rootsweb.com/~adgedge/Research/April%202004/Kincaid%20%20DNA.xls ------------------------------- To unsubscribe from the list, please send an email to KINCAID-request@rootsweb.com with the word 'unsubscribe' without the quotes in the subject and the body of the message