At some point every genealogist will no doubt request a lookup in a database for an ancestor. The database might be in an Archive, a Library, a Museum or it might be in another genealogist's privately held collection of records.
Sometimes a fee is charged for lookup services. Occasionally it is free.
Sometimes your ancestor is found. Often he or she is not. Sometimes what is found is not what you were hoping for.
There Are Different Reactions to a Not-Found Response
As someone who offers a lookup service in that challenging period known as pre-1865 immigration records to Canada, I have experienced different reactions from those customers informed the search was not successful and their ancestor was not found. I have also had negative reactions when their ancestor is found in the record but it is not what they were expecting. I have had a few send angry emails complaining about the fee charged ($16.00 for a lookup in 5 books) I have had a few complain that they wanted more details. Obviously these researchers did not read the description of the databases. It struck me that this is something we genealogists need to talk about.
Why Wasn't My Ancestor Found?
So let's think about why your ancestor may not have shown up in that database.
The simplest and likely most correct answer is that he or she wasn't recorded or wasn't in that spot when you think he/she was, or the database has some missing portions. But the bottom line is that you can't expect your ancestor to be in every single database just because you think (hope) he/she should be.
However there could be other reasons your ancestor wasn't found:
1. You didn't provide enough information to assist the individual doing the lookup. At a minimum you should provide a full name, dates (birth, death, etc) and a location.
2. You misunderstood what the parameters of the database. For example if the record set states it is a database of impoverished immigrants from Ireland between 1834 and 1836, but you are looking for an ancestor who immigrated from Scotland circa 1840, you are looking in the wrong database.
3. You didn't provide alternate or unusual spellings of your ancestor's name. For example my husband's great-grandfather was known as Archie. But his actual name was Achillus. You cannot expect whoever is doing the lookup to know that Archie might be a nickname for Achillus. They will be looking for Archie or the more common root name of Archibald!
4. You didn't read the description of what was in the database. For example I offer a lookup service in a book which I clearly state is an index only containing first and last name and year of immigration as well as details on where the full record can be found, you really should not complain that you expected the full date of immigration, the birthplace of your ancestor and the name of the ship he/she sailed on. (Yes that has happened)
5. Perhaps the database is only a partial database, something rescued when the bulk of the records were lost or destroyed. Perhaps the database has been reconstructed from other sources. An example of this is my Olive Tree Genealogy project to reconstruct missing ships' passenger lists from Holland to New Netherland (New York) 1624-1664. Alternate sources such as court records, notarial records, etc, are being used to find names of individuals leaving Holland for New Netherland on specific ships. But genealogists cannot expect that the names of every single passenger on those ships will be found.
Can I Learn Anything From a Not-Found Response?
Yes! You can note that the specific set of records was searched with no sign of your ancestor. In other words, cross that off your To-Do list!
You can then re-evaluate your thought processes - should you look for more alternate sources for what you are hoping to find, or should you set that aside and make a note that you might not be successful in finding the specific fact you want. Perhaps it simply does not exist. Sometimes it's good to take a break from a challenging ancestor search and move on to something different. Then go back to it at another time.