Sources tell you where information has come from. From this you can judge how reliable the information might be:

1. Some sources come from documents, like a will or a birth certificate, and can be considered reliable. Though even here, some caution might be needed because there may have been a later will or the father on the birth certificate may not be the actual father.
2. Family members are a great source of family facts - parents usually know when their children were born!
3. There is a lot of anecdotal evidence in family trees that has its own interpretation of the facts - read the item in Genalogy Humour called How will you be remembered?
4. Some information is found on web sites and it is not always possible to ascertain how reliable the information is if it does not in turn provide us with its source.
5. Much of the data in this family tree comes from other family tree researchers who do not always identify their source. Data from my brother is a case in point, but it runs in the family - I have often forgotten to say where my information has come from!

When you are contributing information try and remember to tell us where it comes from.