H2 History Exam Skill: How to Use Source Omissions

Today we will focus on one very common issue I see not only among my own students, but across the wider H2 History cohort as well: the usage of source omissions.

At prelims, many students wrongly faulted sources simply because “they don’t tell us everything.” For example, writing “This source is not reliable because it does not mention Stalin’s responsibility.”

This approach does not earn much credit, because all sources leave things out. Examiners want to see you think carefully about why a source omits something — whether through lack of knowledge or deliberate choice tied to provenance.

Common usage of omission that will not score highly

“This source is not reliable because it does not tell us everything about Stalin’s role in the Cold War.”

This will not be credited highly because this is a statement that could be made of any source - any source can be faulted for failing to include something. It shows no thought about the context or author.

Stronger usage of omission links the missing content directly to the provenance of the source — showing how the author, purpose, or context explains why the omission occurred.

This can take two forms: (1) deliberate omission, where the author leaves something out to serve a purpose (e.g. propaganda, political agenda); or (2) omission through lack of knowledge, where the author could not yet know key information at the time. Explaining which applies — and how it shapes the source’s value for the enquiry — is what examiners reward at the higher bands.

Stronger usage of omission 

“The source is limited because it does not mention Stalin’s purges of the 1930s. This omission is linked to its provenance: it was published in Pravda in 1936, when Soviet newspapers were used to glorify Stalin’s leadership and present only successes in industrialisation. This omission reduces its utility for judging Stalin’s repressive methods, though it is still useful for understanding how propaganda was used to present him as a strong leader.

In this case the student explains what is missing, why it is missing, and how that affects usefulness, instead of just saying “it leaves things out.”

(A) Omission Through Lack of Knowledge

Omissions can exist because the author simply did not or could not know more.

An example of explanation of the omission: A British newspaper article from 1947 does not mention the Soviet blockade plans for Berlin. This is not a deliberate omission but a reflection of the fact that Western journalists at the time were not aware of Stalin’s intentions. This limits its utility for explaining Soviet planning, but it is still useful for showing contemporary Western fears of Soviet aggression.

(B) Deliberate Omission

Omissions can also be purposeful, shaped by the source’s agenda.

An example of explanation: “A Soviet school textbook from the 1960s omits mention of Khrushchev’s secret deal with Kennedy to withdraw missiles from Cuba. This omission reflects its purpose: to present the Cuban Missile Crisis as a Soviet victory, rather than a compromise. This limits its utility for judging the reality of Soviet foreign policy, though it remains useful evidence of how the USSR wanted its citizens to view the Cold War.”

If you identify an omission, always ask yourself: “Why does this omission exist?

I hope this helps you avoid this common omission mistake in your next source-based essay. If you’d like more guidance, examples, or revision notes, feel free to explore more resources at: https://www.h2historyguides.com