Have you ever played the children’s game “Telephone?” It is played by a large group of people. The first person whispers a phrase into the ear of a second person, who whispers it to a third person, and so on. The last person then speaks the phrase out loud. Invariably, after twenty or thirty people, the phrase and its meaning have changed dramatically or even beyond recognition—just in the process of a few minutes. The story of the game is from the trenches of World War I: a message sent down the trench line, “Send reinforcements, we’re going to advance” became “Send three and fourpence, we’re going to a dance.”

Like the game “Telephone,” historical information can become unreliable very quickly. Thus, one of the most important concepts in genealogy research is that of source quality: how reliable is the information you find? As discussed earlier, source quality is critical for any genealogist who wants to know that his or her family tree is more than just fiction. To back up the names, dates, and other information you have or find, you should always seek to have real documents, tight logical reasoning, waterproof critical analysis, and solid, trustworthy sources. Without this background foundation, your research may be completely wrong no matter how much effort you spend.

Researchers distinguish between different qualities of sources and records, depending on how trustworthy the source of the record is. Since sources can provide conflicting information, it is important to be clear on what the different sources are and how much weight to give to any source.
Firsthand accounts by people who experienced events or facts and wrote them down immediately are, in general, clearly the best, since these are from people who have actual knowledge. As the source becomes removed from the actual event or facts, either in time or people, the information becomes less trustworthy. The two most important and trustworthy levels are primary and secondary sources.

Primary sources.

Primary sources are eyewitness accounts created during the time period that you are searching. Naturally, these aren’t foolproof—like modern eyewitness accounts, the source and his or her perspective may be biased, incomplete, uncertain, wrong, or lying. Just think about witness testimonies given on any courtroom television show. Do the witnesses always know and tell the pure, unvarnished truth? Historical witnesses can be the same.

It is thus important to always consider whether and how primary source material may have it wrong. Despite these limitations, primary sources are the best thing we have to go on for facts and events from long ago.

Primary sources can be found in many different types of record types, such as legal documents, census records, journals, and newspapers, among many others. Books can also be primary sources if they were firsthand accounts written during the time of the book’s study.

Secondary sources.

A secondary source is created by someone who did not have firsthand knowledge. The author did not experience the events or facts in question. Thus, for example, most history books are secondary sources, as they are typically written long after the facts have transpired and by historians who were born much later.

Source types together.

Primary and secondary sources can both be found in the same document, depending on which information is referred to. For example, a death certificate typically provides information about the person who died—the decedent—and his or her parents. This information is often provided by someone who knew the decedent personally but did not personally know the decedent’s parents. Thus, the information about the decedent would be primary source material, but information about the parents, such as their names and places of birth, would be secondary. The information about the person who died is very likely to be correct, but the information about the parents would need to be considered carefully to determine how likely it is to be correct, since the information was given by someone who did not have firsthand knowledge.