How to find contradiction between sources

Contradiction is the ability to compare two separate sources and find information that differs between them. Contradiction is when the things said by the two sources cannot both be true: one has to be wrong.

For example

If one source said that Germany won World War One and another source said that Britain won World War One, they clearly cannot both be right. One of the sources has to be wrong. This is a point of contradiction.

When a second source provides the opposite information to the first, the second source is considered to contradict (e.g. disagree with) with first.

Finding contradiction between sources helps you to determine how accurate or reliable a particular source is.

Watch a video explanation on the History Skills YouTube channel:

Please be aware!

Sources may provide different kinds of information that may not prove contradiction. Contradictory is only information that is provided by two separate sources that cannot be true at the same time.

In order to identify information that is disagreed upon by two different sources, following these steps:

1. Read the first source and summarise the key points of historical information they provide. Using direct and indirect quotes helps with this.
2. Read the second source and summarise the key points of historical information they provide. Using direct and indirect quotes helps with this.
3. Compare the two different summaries that you wrote and then look for conflicting information in both lists.
4. Any information provided by one source that is contradicted by the other can be used. 

To help you complete the above steps successfully, you can use a Venn Diagram, or a table like the one below to organise your thoughts:

That is perfectly fine. Most of the time, sources will not provide information that is contradicted by other sources. This may be because they are talking about different things, or they provide information that is very similar.

If you cannot find direct contradiction between your sources, use other analysis skills to evaluate them.

Demonstrating source contradiction in your writing:

The earlier interpretation of Bean claimed that plans for the landing were undermined by currents that forced the troops’ landing craft north of their intended landing place, while Winter argues that this is wrong because the Anzacs were landed where they were intended (Bean, 1918, 435; Winter, 1991, 12).

Two sources disagree about whether this was a good idea: Hammond (1997, 201) says it was a mistake, but McCoy says it was a good idea because, “…” (2001, 28).

Whilst Hammond (1997, 201) believes that this was a mistake, McCoy seems to suggest that there was a positive strategy behind the decision, arguing that “...” (2001, 28).