Is Our Tree Better Than My Tree? The Benefits and Pitfalls of Collaborative Genealogy

[Published in Avotaynu XXIX, No. 2, p. 7.]

by E. Randol Schoenberg[1]

Until recently, we began by building our own individual family trees.  We started with our parents, siblings, children, spouses and continued to fill in as much as we could.  When we reached a branch where we did not know the information, we turned to a relative or searched for records, perhaps even hired a professional genealogist.  With time and patience, many of us built nice trees, even large ones, with hundreds or thousands of people.  We documented our results with records and photographs.

Most of us eventually computerized our trees, using programs such as Family Tree Maker or Reunion.  We submitted GEDCOM files to Beit Hatufsoth or JewishGen’s Family Tree of the Jewish People (FTJP).  Some of us even published our trees on the Internet or in books.  But what we never did was allow someone else to work on our tree.  We did not collaborate.  The tree was ours and no one else’s.  It did not grow without our involvement and it did not venture beyond where we wanted to go.

All that has changed in the past several years with the advent of collaborative genealogy.  A product of the connectivity of the Internet, collaborative genealogy allows a number of different people to work together remotely on one connected tree.  The result has revolutionized the field of genealogy, and Jewish genealogists have been at the forefront of this new development.  Instead of speaking of trees of thousands, we now talk of millions.  Instead of starting from scratch, many people are coming to genealogy as a result of an invitation to an existing tree that they are asked to join and help build.

Separate Collaborative Trees (, MyHeritage)

Inviting Collaborators to Your Tree.  A number of collaborative genealogy websites exist to facilitate cooperative tree-building. The most popular genealogy websites, for example and MyHeritage, have offered collaborative tree building options to their customers.  On these sites, users build their own trees (or upload GEDCOM files) and then invite people on the tree to join by entering their e-mail addresses.  The invited users can then help to build the tree by adding new profiles and information.  The potential for growth is great.  Your first cousin shares two grandparents with you.  He can add in his other two grandparents and invite cousins from the other side of his family.  So can his spouse.  In this fashion, the trees start to grow in this fashion in all directions, the only limit being the industry of the invited members.  The largest trees of this type generally have fewer than 100,000 profiles.

Merging Duplicates, Adding Sources, Finding Matches.  The better sites allow merging of duplicate profiles, so that if a person appears more than once in the tree, the profiles may be joined together seamlessly.  This avoids unnecessary duplication of profiles in the tree.  Sites such as and MyHeritage also offer the ability to connect records from their enormous databases to the profiles in the tree, which is a huge bonus for those who like to have their trees well documented.  Users also have the ability to search the unconnected trees of other users and contact them to confirm or trade information.  The companies even have developed algorithms to detect data matches and suggest them to the customers.  Finding these matches allow users to glean new information for their trees.  Ancestry recently added a feature to find matches on Facebook to allow users to invite their relatives to the tree through that website.

Mergeable Collaborative Trees (Geni, WikiTree, WeRelate, FamilySearch)

Finding Relationships.  The collaborative model was further improved by Geni, a California company recently acquired by MyHeritage of Israel. The key innovation was the ability to merge separate trees together. What began as thousands of separate trees has evolved, over time, into one enormous World Family Tree of over 70 million profiles, including 2.9 million connected users.[2]

While many thousands of separate trees still remain on Geni, the real action is in the World Family Tree.  A genealogist who can connect to that tree instantly is connected to an enormous web of related profiles.  Using Geni’s far-reaching relationship finder, researchers can determine the closest path between two profiles on the tree.[3]  Because of a computational resource limit, however, the algorithm generally finds profiles that are either direct relatives, or are otherwise no more than twenty steps away (e.g. an uncle’s wife’s cousin’s sister’s nephew).

Many users find it fun to see how they are connected to famous people in the tree. [4] The more popular Jewish ones range from King David[5] and Rashi, to Albert Einstein and Jamie Lee Curtis.  At this point it would be difficult to find a Jewish celebrity whose tree is not already part of Geni’s World Family Tree.

Curators. Geni’s approach has attracted a host of excellent genealogists, eager to build the World Family Tree.  About 120 of them have been selected by Geni as volunteer curators, who have been given the ability to resolve disputes, untangle incorrect merges and lock problem profiles.  Not surprisingly, about 10 percent of the curators are Jewish, with expertise ranging from biblical to modern times, and everything in between.[6]  The many non-Jewish curators also are extremely knowledgeable and helpful.

One of the interesting aspects of Geni is the ability to compare the working behaviors of genealogists from all over the world.  Some have exhibited incredible feats, adding thousands of profiles, records, sources, photographs and documents, and completing thousands of merges and data conflict resolutions every month. Even those who consider themselves very active and experienced in Jewish genealogy would be quite amazed at what some other people are capable of doing.  Each curator brings his or her own expertise and interests to the task.  Collaboration allows these genealogists to learn from each other and work as a team to make Geni a better environment for building the World Family Tree.

Projects.  Geni also enables users to create projects, allowing close collaboration on specific areas of research by way of project discussions and adding profiles to the project.  The Jewish Genealogy Portal with several hundred collaborators is an umbrella project with a directory to many of the Jewish projects on Geni.[7]  Two of the largest are the Auschwitz-Birkenau project, with more than 5,000 profiles, and the Jews of Kraków, with more than 13,600 profiles.[8]  Geni already has hundreds of significant Jewish projects with more started every day.

Massive published genealogies have been entered into Geni and indexed in projects.  These include Neil Rosenstein’s The Unbroken Chain,[9] Malcolm Stern’s First American Jewish Families,[10] and Georg Gaugusch’s Wer einmal war.[11]  While some data from these books may still be missing, the skeleton of the tree is all there and is being improved on daily with information and records not include in the books, such as photos, documents, sources and links to living descendants and relatives, many of whom are Geni users.

Web Searchable and Crowd-Sourced.  Although privacy restrictions make the lower parts (with living profiles) less publicly accessible, Geni’s tree most closely resembles a Wikipedia model in that the public portions of the tree are searchable on the Web.  This feature distinguishes Geni from all of the other collaborative tree platforms, and has made it a magnet for new users.  Because of the large number of users, Geni’s tree is dynamic, not static.  It is constantly being changed and improved.

Working on Geni is like working on an enormous jigsaw puzzle with thousands of other people.  You get the advantage of everyone else’s work, and they all get the advantage of yours. With the power of crowd-sourcing, Geni allows genealogists to work together on much larger projects than anyone working alone could ever tackle by himself.[12]

Drawbacks to Collaboration

Mistakes.   With the numerous advantages of collaborative genealogy come some significant drawbacks.  Allowing others to access and modify a tree sometimes permits mistakes to creep in.  Of course, the same openness also allows users to correct mistakes.  Often I hear people complain that they looked at Geni or WikiTree and found mistakes–but that may turn out to be one of the great strengths of these platforms.   Not only can individuals find the mistakes, they also can fix them–and for everyone.  This is the model that Wikipedia used eventually to supersede The World Book and Encyclopedia Britannica.

With over one million collaborators correcting and improving the tree, there is simply no doubt that the World Family Tree on Geni is becoming not only the largest, but also the most accurate and well-sourced tree available in most areas.

Working with Difficult People.  As with all works in progress, collaborative trees sometimes present difficulties, as, for example, when competing versions of a tree are merged and discrepancies are discovered.  Working out the differences with others may be challenging.  As every experienced genealogist knows, records often conflict or are unclear.  Family stories may turn out to be fabrications.  Hidden relationships sometimes reappear.  The best collaborative genealogists understand that working together with others means sometimes being open to accepting a different point of view.

Lack of Privacy.  One potential drawback of collaborative genealogy, especially on Geni, is that everyone gets to see what you are doing.[13]  If you like to keep something private, don’t put it on the Internet.  Some family histories are better left unpublished, but for most genealogical data, publication on the Internet causes no harm.  Some people fear so-called “identity theft,” but that term is in fact really a misnomer and more of a marketing slogan for companies trying to sell security. What people call “identity theft” is in fact just garden variety fraud – either by way of batch theft of customer credit card data from merchants, or fraudulent credit card applications by people who personally know the victim and already have access to his or her personal identification information.  As far as I have been able to determine, there has not been even one documented case of fraud involving use of an online family tree.

The lack of privacy can also have advantages, as it allows others to find connections and assist in building the tree alongside you.  There is no better way to make a breakthrough than to make your tree public so that some other relative or genealogist can find it.

Time and Expense.  Moving to a collaborative tree can be expensive and time-consuming.  Most of the collaborative tree platforms have different levels of membership.  Often there is a fee for the service, or for certain aspects of it.  Some allow users to start for free, but then charge for added features.  Shop around and make sure to pick the price structure that is best for you.  Adding a tree to a collaborative platform can be as easy as uploading a GEDCOM file, or as difficult as re-entering all the data by hand.  In its early years, Geni grew exponentially by allowing GEDCOM imports, but the imports eventually created so many duplicate profiles, that GEDCOM importing was stopped.  People with large trees (more than a few thousand profiles) almost always find that much of the tree is already on another collaborative tree in the database.  Often it is better to connect with and join an existing collaborative tree than start one of your own–but the effort needed to enter new data, or sources, by hand may be daunting.  Fortunately, it is usually possible to find collaborators to help with data entry.

Who owns the Tree?  Those who start or join a collaborative tree project on the Web essentially give up ownership of the tree and agree to share it with others (and the company that owns the platform).  That means that if the platform disappears, so could all your work. Thus far, we do not see much risk of any of the major collaborative tree projects disappearing.  The more likely scenario is exemplified by MyHeritage’s purchase of Geni, as one collaborative platform is acquired by another.  The databases created by collaborative genealogists have become very valuable assets, and it seems unlikely that the data ever will disappear completely.  Nevertheless, most of the platforms allow at least a limited ability to download a GEDCOM file of some size to protect your work and that of your closer collaborators.


In the past decades, Jewish and non-Jewish genealogy has focused on data aggregation rather than tree building.  The incredible resources created by JewishGen or JRI-Poland, for example, or with the digitized indexing of the U.S. Census, have tended to make us think of the Internet as only a source of data rather than as a platform to build trees together.  Some people are disappointed not to find more information about their own families in the various collaborative trees.  When they see a tree that is incomplete, without sources, or lacking the answers they seek, they object and look elsewhere.  This misses the point, I think.  Genealogy is about the tree and the relationships we all have to one another.  Although by now we have learned not to believe FTDNA and 23andMe when they predict that we’re second cousins with another Jew in their database, we can be certain that there is a connection somewhere, perhaps lying just a few generations beyond where the records stop.

Collaborative trees are not a substitute for records research; they are the way to structure the results of that research so that it is available for others to build on.  This is how knowledge and science advance, with one person working off of and improving the work of another.  Without collaborative genealogy, we will all be limited in our focus, able to see only the relatively small web of relationships that we work on by ourselves, and never seeing the majesty of the larger web that includes us all.



[1] E. Randol Schoenberg,, is a board member of JewishGen and the Co-Founder of JewishGen’s Austria-Czech Special Interest Group. He moderates the Austria-Czech mailing list and website, and is also the author of the Beginner’s Guide to Austrian-Jewish Genealogy and the co-author of Getting Started with Czech-Jewish Genealogy. Schoenberg is a volunteer curator on, and one of Geni’s most active users, managing about 100,000 profiles  Professionally, he is an attorney and serves on the boards of various philanthropic, artistic and educational organizations. He presently serves as President and Acting Executive Director of the Los Angeles Museum of the Holocaust.

[2] The big trees on WikiTree, WeRelate and FamilySearch are far smaller.  WikiTree presently has 5.2 million profiles on its big tree.  WeRelate has 2.4 million.  The LDS Church recently released its new collaborative Family Tree which has the potential of competing with the others.  But it remains to be seen if this or any other platform will be able to catch up with Geni.  Geni users are adding new profiles to its World Family Tree at a rate of 7 million per year. See

[3] The closest path is the one with the fewest steps between nodes on the tree.  Geni shows the closest blood relation, or else the closest connection (ie. cousin to cousin to cousin).

[4] It is also fun to see the relationship paths between famous people: “Sigmund Freud is Ludwig Wittgenstein’s third cousin once removed’s husband’s sister’s husband’s first cousin’s 1st husband.” or “Franz Kafka is Gustav Mahler’s wife’s husband’s first cousin’s wife’s sister’s husband’s first cousin’s husband’s first cousin’s husband’s first cousin once removed.”  Of course, the point is that we are all “related” in this fashion.

[5] Geni tells me that King David is my 94th great-grandfather.  Naturally this path requires a number of leaps of faith and the use of undocumented, perhaps mythological genealogies extending through areas well beyond my expertise.  My own comfort level does not extend much beyond my 11th great-grandfather Samuel Phoebus Lämml (Teomim-Munk) (d. 1616 Vienna). But it is interesting to find that the number of generations is at least somewhat plausible.

[6] Presently, the Jewish curators include:  Hatte Blejer, Adam Brown, Yigal Burstein, Ofir Friedman, Kevin Janit, Jaim Harlow, Itai Hermelin, Erica Howton, Shmuel Kam, Pam Karp, Rafi Kornfeld, Itai Meshulam, Malka Mysels, Peter Rohel, Randy Schoenberg, Alisa Sharon, Marco Soria and Marsha Veazey.  See

[8] The Krakow project,ów-Poland/12917, spearheaded by curator Pam Karp, is an attempt to move all of the data (70,000 profiles) from Dan Hirschberg’s Krakow website ( over to Geni, where it can be integrated with the rest of the World Family Tree and can be augmented by the community with records, photos and links to living descendants.

[12] In the field where I do most of my work, Austria, Bohemia and Moravia, Geni has allowed us to link together pretty much every Jewish family from that region.  The project is enormous and ongoing, but with the wealth of records that are increasingly becoming available, and the number of collaborators working on them, the Austria-Czech-Jewish part of the tree is likely to become the most dense and detailed tree ever created for Jewish families in a particular region.

[13] Geni and all the other platforms have varying privacy settings.  On Geni, living profiles are set to private and not searchable on the Web.  Nevertheless, as a rule of thumb, if you don’t want anyone to make the information public, do not put it on the Web in any fashion.

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