Primary and Secondary Sources
Many people have asked me about sources and the difference. There is a lot of information about sources on the internet but some people are still confused.
A primary source is something that comes from the time that the historian is studying.
For instance if a historian is studying the First World War, then letters and diaries written by the soldiers, the uniforms and the weapons are the primary sources. If a soldier who fought in the trenches wrote his memories of the war a long time after the war it is still a primary source.
Secondary sources are sources which do not come from the time the historian is studying. These sources have got their information from other sources. Books about the first world war by historians or school textbooks about the First World War, are examples of secondary sources.
with the exception of the 1911 census, returns are not primary sources, they are secondary sources. The information they contain may have been transferred through several people. The individual's details given to head of the house; the head of the house who wrote out the Householders Schedule which was then handed to the enumerator, who then transferred it to the CEB, which itself was subjected to the rules of the census particularly over the classification of occupations. Finally the Census Office clerks may have made alterations. There were mistakes.
I think the diagram shown below, of the various sources historians can use, will make it easier to understand.