Online database programs make huge numbers of genealogical source records available at the click of a mouse or trackpad. But is that all there is to gathering source records? Unfortunately, the larger database programs make you think you have gathered all the information when, in fact, you are leaving large portions on the table. Here is an example from FamilySearch.org showing how much information you will miss unless to examine the original record carefully. By the way, I am using FamilySearch.org only as an example, this same issue arises frequently in many online database programs.
FamilySearch.org has recently added a very useful tool for extracting data for all of the members of a target ancestor's family at the same time. I decided to search for a 1900 U.S. Census Record for my Great-grandfather, Henry Martin Tanner. After locating Henry in the Family Tree, I noted that a source citation with a link to the original record already existed for Henry Martin Tanner, but in order to attach the record to all of his family members, I detached the record, located it again in the Historical Record Collections and after attaching it to Henry again, I got the choice to add additional family members. Here is a screenshot of the top portion of the screen showing the family members to which the Census Record was added.
All of the individuals in green were listed on the original record with Henry and Eliza as their parents. Here is a screenshot of the original 1900 U.S. Census record for reference.
The above extraction from the record done by FamilySearch.org Family Tree, shows the original record on the left and lists the individuals who appear in Family Tree on the right. The ones in green match those in the source. Obviously, if there is not a correct match, then the source record should not be attached. But let's focus on the family members in Family Tree that are not matched in green. If you look carefully at the original source record, you will see that there are matches for these individuals also. However, they do not appear in Henry's family on the U.S. Census record. Why is that? In this case the second Tanner entry for Emma Ellen Stapley Tanner and her children as shown as a separate household. This was sometimes the case with polygamous families. But the important point here is that the search did not automatically attach these further children and family members of Henry Martin Tanner. If I happened to search for a Census record for Emma Tanner, I might find it and add it in. But more importantly, the original record needs to be reviewed carefully. If the researcher did the search, he or she would have very easily found the second family of Emma E. Tanner.
The important thing to remember here is not that FamilySearch.org did not add the second family automatically, but that in nearly every case, it is extremely important to view the original record rather than just a summary or extraction of what someone else believes is important in the record.