There are a few concepts you need to understand that will help you evaluate every source of information you use in your research. You evaluate sources in three different ways:
Is the source original or derivative?
When you are looking at tax rolls at the courthouse you are looking at original records. If you are looking at a book of tax roll abstracts that someone compiled then you are looking at derivative records. If you are looking at a marriage book in a courthouse you are looking at original records. If you are looking at a marriage index on Ancestry.com then you are looking at derivative records.
You use derivative records to lead you to the original. If I find my ancestor in a marriage index the index will give me the county and the date. I can then write to the courthouse in that county and get a copy of the original license/certificate. When at all possible, you want a copy of the original. Compilers are human and they make mistakes. You will never know if what the compiler recorded is what is actually on the document unless you see it yourself.
Is the information primary or secondary?
A death certificate is a primary source of a person's death. It was created at the time of death for the purpose of recording the death. The death certificate will also record the person's date of birth, however, the death certificate would only be a secondary source for the birth. A birth certificate would be a primary source for the birth information. You could make the argument that the birth information is primary IF the informant was someone actually present at the birth (mother or father).
Is the evidence direct or indirect?
If a tombstone says born 04 Jan 1820 that is direct evidence of the exact birth date. If the tombstone says, died age 18 years, 4 months and 3 days you can calculate when the person should have been born but this is only indirect evidence of the birth date. If you have a 1900 census page where the relationships are recorded then you have direct evidence that a listed child is the son/daughter of the head of household. If you are looking at an 1850 census page where relationships are not recorded then you have indirect evidence that a child listed in the household is the son/daughter of the head of household. Indirect evidence is commonly known as circumstantial evidence.
Understanding the three ways you can classify a source will help you evaluate how much weight/confidence you give that source. Tomorrow you will learn what other questions you need to ask yourself when looking at a piece of evidence.
Copyright © 2012 Michele Simmons Lewis