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Louis Kessler’s Behold Blog

GEDmatch - Are You In or Out? - Tue, 10 Dec 2019

It’s already day-old news. GEDmatch has been purchased by Verogen.

For some of the reporting on this, see the following news posts:

For some of the details and opinions of expert genealogists and genetic genealogists, see the following blog posts:

Because of the new confirm acceptance requirements, and more stringent re-opt-in requirements for European residents, the number of matches available is going down for police searches.

    But not just for police searches. For everyone’s searches.

    One month ago, on November 5th, my 3000th closest match at GEDmatch shared 30.5 cM with me. Today my 3000th closest match shares 27.9 cM.  I have 699 matches at GEDmatch sharing from 27.9 cM to 30.4 cM. That means I have lost 23% of my matches at GEDmatch.  You likely also have as well.

    I’m definitely staying. What are you going to do?

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    DMT - The Horizon Effect - Tue, 3 Dec 2019

    In Version 3 of Double Match Triangulator, I added the ability to specify the smallest segment match that DMT would consider to be part of a valid triangulation (default 7 cM) and the smallest segment match that DMT would consider to be a valid single match (default 15 cM).

    A situation that can happen when you get close to the triangulation limit is something I will call the horizon effect.  If two of the three valid overlapping matches in a triangulation are over the triangulation limit (i.e. >= 7 cM), but the other is slightly under it (e.g.  <= 6.9 cM), then you’ve got a problem. DMT will eliminate the small segment and incorrectly classify the triplet, not as a triangulation, but as a Missing A-B or Missing B-C match.


    Is this a Major Problem?

    To be honest, I would say no.

    1. Leaving out valid triangulations only gives less data to work with but is not a problem.
    2. The misclassifying of a triangulation as Missing B-C might allow the B-C match to be used incorrectly as an inferred match.
    3. The misclassifying of a triangulation as Missing A-B would get the A-C match to map onto the incorrect parent.

    But cases 2 and 3 shouldn’t be too concerning since DMT uses a consensus approach. If the majority agree it is a triangulation through a particular common ancestor, then the (hopefully) fewer misclassified matches will be outnumbered by the good ones.


    A Possible Improvement

    Even so, I’d like to see if I can address this horizon effect and do something to reduce the number of misclassified matches. I came up with an idea.

    Currently, DMT ignores all matches in the Person A and Person B match files that are below the triangulation limit. I can change that so that Person A segment matches that are less than the limit will still be compared to Person B matches.

    e.g. If we have a B-C match of 7.2 cM that overlaps with an A-C match of 6.8 cM and an A-B match of 6.7 cM, then DMT will now say that is a triangulation.

    What is the extra bit on the B-C match?  Well it could be an extra bit at either end that matches by chance, or it could be that B and C are more closely related than A and C and have a larger match between them.

    I know some A-C and A-B matches below the triangulation limit will then be included, but that limit is no magic number. Segments above the limit are not necessarily valid, and segments below it are not necessarily invalid. We are simply using the limit to pick the point at which we expect that most triangulations will be valid.


    Can’t Always be Done

    DMT 3’s inclusion of smaller A-C matches for triangulations will only work if the match data contains segments smaller than the limit selected. If the limit you select in DMT is 5 cM, but your match data does not include segments smaller than 5 cM, then DMT will not have any smaller A-C segments to work with.

    In that case, the horizon effect will occur more often and DMT’s consensus approach will have to be relied upon to produce reasonably logical results.

    Lower limits of individual segment matches at each company are:

    • Family Tree DNA:  1 cM
    • 23andMe:  5 cM  (on the X chromosome:  2 cM)
    • MyHeritage DNA:  6.1 cM
    • GEDmatch:  default 7 cM, but you can reduce that down as low as 1 cM

    If you’re using GEDmatch, you could download just Person A’s segment matches to a slightly lower limit. e.g. if your triangulation limit is 7 cM, try downloading A’s segment match file to 5 cM.  I would not go as low as 1 cM at GEDmatch. Doing so is known to introduce too many false matches. See False Small Segment Matches at GEDmatch.

    If your segment match files go down to a certain cM, e.g. 6.1 cM, then you could raise your triangulation limit in DMT a bit, say to 8 cM.

    Personally, I don’t think it’s necessary to worry too much about this fine tuning. DMT should give reasonably similar results whichever way you do it. Really, you’d be much better off spending your time trying to identify common ancestors of more of your DNA relatives, as that will improve DMT’s results the most.


    So How Did It Do?

    I made the above changes to my working version of DMT and ran the same data that I did for my 23andMe article.

    This time around, DMT included 175 A-C segment matches between 6 and 6.99 cM and 169 segments between 5 and 5.99 cM. With the 892 people I match, these extra segments increased the number of triangulations I have from 1355 to 1757, an increase of 402 triangulations. 7 cM is at the lower limit of valid triangulation size, so some of those that include segments down to 5 cM might not be valid and be by-chance matches. Picking a very conservative number out of my head and saying that only 80% of these were valid matches, then this adds about 320 new valid triangulations and about 80 false triangulations.The power of consensus again should work to use that extra data advantageously.

    Final results are that 816 (up from 790) of the 892 people I match with are now assigned clusters, and grandparent mappings now cover 52.8% of my paternal side, up from 46.1%. 

    The improved grandparent mapping (from DNA Painter) is:

    image

    Compare this to the 46.1% diagram from before, and I you’ll have a hard time finding the differences, which is good:

    image


    Update to DMT Coming

    I think it’s worthwhile including this small improvement in an update to DMT. I’ve got a few more small fixes/improvements to make and one other idea for using the results from one company to initialize the run for another company. So hopefully within a week or two, I’ll have a new release of DMT available.

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    Genealogy is Virtually Everywhere - Wed, 13 Nov 2019

    Last night, I attended a talk of a prominent genealogy speaker. This is a speaker who keynotes conferences and attracts thousands to her talks.

    Diahan Southard gave her talk “Your Slice of the DNA Pie”, and I watched it on my computer at home. It was a presentation of the Virtual Genealogical Association, an organization formed in April 2018 to provide a forum for genealogists to connect online. Webinars such as Diahan’s are just one of their offerings. Membership is just $20 a year.

    image

    The VGA just completed their first highly successful Virtual Conference. There was one track with 6 well-known genealogical speakers on the Friday, 6 more on Saturday and 5 on Sunday, so the Conference lasted three full days. In addition, three prerecorded talks were included. All talks are available to attendees for re-watching (or watching if they missed the live talk) for the next six months.

    image

    Like any physical conference, handouts by the speakers were made available to attendees for each of their talks individually, or as a syllabus. Attendees were told about a surprise bonus at the end of the conference which was a special offer from the National Institute for Genealogical Studies of a free 7 or 10 week online course worth $89 authored by two of the VGA Conference speakers: Gena Philibert-Ortega and Lisa Alzo.

    The VGA Conference was hosted and directed by their delightful president Katherine Willson. She said they were very happy that over 250 people paid the $59 (members) or $79 (non-members) fee to attend the 3-day online conference, something that was really the first of its kind. 

    The VGA plans to continue these annual conferences. The next is already scheduled for Nov 13-15, 2000, so be sure to block those days off now in your calendar.

      
    What is Virtual Genealogy?

    Most of us are used to attending live genealogy conferences. You know, the ones you have to physically be there, be semi-awake, have showered, look decent, be pleasant even if you’re not feeling pleasant.

    They may be offered by your local genealogical society in the city you live, a regional conference in a city you can drive to, or a national or international conference that you usually have to fly to. Live conferences require many people to organize and run. They are expensive to put on, require booking of a venue, obtaining of sponsors to cover the costs, vendors to fill an exhibition hall, rooms and logistics to enable the speakers to speak, etc., etc.

    By comparison, I would say:

    Virtual Genealogy simply is any genealogical activity you can do on your computer or smartphone in your pajamas.

    This includes everything from:

    • attending online lectures
    • taking online courses or workshops
    • watching conference livestreams
    • communicating with other genealogists via social media
    • researching your family online
    • using genealogy software to record your family tree information

    It’s only in the past couple of years that many of these virtual genealogical activities have become available. I can truly say now that you can be a bedroom genealogist and learn and do almost everything you need to without slipping out of bed (as long as your laptop or smartphone is within arms reach).

    This wasn’t possible just a few years ago, but it is possible now.

      
    Legacy Family Tree Webinars

    The big kid on the block as far as online genealogy lectures goes is Legacy Family Tree Webinars. They have been around since 2010 and started off simply as a way for the the genealogy software program Legacy Family Tree to make instructional videos available for their software. They offer a webinar membership for a $50 annual fee giving you full access to their webinar library. Many new webinars on any and every topic are made available free for the live presentation.

    In August 2017, Legacy software and the Family Tree Webinars were purchased by MyHeritage. MyHeritage has allowed them to continue running, with the added advantage of making MyHeritage instructional videos and talks available to everyone for free.

    The long-time host of most of the videos is Geoff Rasmussen. He just celebrated Family Tree Webinar’s 1000th webinar in September with this wonderful amusing behind-the-scenes video.

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    Family History Fanatics

    Another not-to-be-missed webinar producer is the family of Andy Lee, Devon Lee and their son Caleb Lee, who call themselves Family History Fanatics. They have their own You Tube channel with 16.7 K subscribers where they post their numerous instructional videos and live streams.

    image

    They also produce online webinars and workshops which are well worth the modest $30 ($25 early bird) price they charge for them. Their next is a DNA Workshop: Integrated Tools that will be three instructional talks of 2 hours each on Dec 5, 12 and 19.

    They also from time to time host one-day eConferences. I paid the $20 early bird fee to attend their A Summer of DNA eConference last August, which included 4 talks by Daniel Horowitz, Donna Rutherford, Emily Aulicino and Leah Larkin.

    Their next eConference will be January 25 called “A Winter of DNAVirtual Conference”.  It will feature four DNA experts. I know three of them will be Jonny Perl (DNA Painter), Paul Woodbury (LegacyTree Genealogists) and myself.

    I have given many lectures at genealogy conferences around the world, but this will be my first ever live webinar. It will be about double match triangulation and the ideas behind it and what it can be used for. I’m really looking forward to this.

    Andy doesn’t have the details up yet for the January conference but likely will soon and will then accept registrations. I’ll write a dedicated blog post when registration becomes available.

      
    APG

    The Association of Professional Genealogists (APG) has webinars for anyone interested.

    The APG also has a Virtual Chapter (membership $20 annually) with monthly online presentations by a prominent speaker.

      
    Live Streaming of Genealogical Conferences

    Another wonderful trend happening more and more is the live streaming now being offered by genealogy conferences. Many of the livestreams have been recorded and made available following the conference, so you don’t always have to wake up at 3 a.m. to catch the talk you want.

    MyHeritage Live in Amsterdam took place in September. They have made many of the 2019 lectures available. Lectures from their MyHeritage Live 2018 from Oslo are also still available for free.

    The first ever RootsTech in London took place last month. A few of their live stream videos have been made available. You can find quite a few Salt Lake City RootsTech sessions from 2019 and from 2018 still available for free.

    The National Genealogical Society offered 10 live stream sessions for their conference last May for $149.

    With regards to big Conferences, nothing compares to being there in person. But when you can’t make it, you can still feel the thrill of the conference while it happens with live streams and enjoy later the recordings of some of their sessions.



    What’s Next?

    My next webinar I plan to watch is another Virtual Genealogy Association webinar: "Artificial Intelligence & the Coming Revolution of Family History" presented by Ben Baker this Saturday morning, Nov 16.

    Never stop learning.

    What’s next on your agenda?

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