Suppose your great-grandfather’s name was Abram Farbsztejn and a search produces birth records for three Abram Farbsztejns over a ten year span, all in the same town or perhaps in nearby towns. They could be unrelated but more likely, they are grandchildren of an Abram who died a year or two before the first grandson was born. In some cases, you may even find the earlier Abram’s birth entry and, if you’re really lucky, you may spot the marriage of Abram and his wife Ruchla Bajla Goldsztejn.
Goldsztejn! You heard her maiden name was Gold. Now, you really get excited! You scan the earlier birth indices for the birth of a Ruchla Bajla Goldsztejn. Not only do you find Ruchla Bajla, but three other Goldsztejns -- all registered with Ruchla Bajla and all with consecutive Akt numbers.
In that moment you are likely staring at the names of three of your great-grandmother’s siblings that you never knew about. And, now that you know their given names, there’s always the chance you can find marriage records for each one of them, twenty or thirty years later… and it goes on and on.
Of course, you must examine the original records…not only to verify your assumptions, but to glean all the information, and to find out the actual birth dates because four births registered in a row does not mean the birth of quadruplets.