Common Knowledge in Academic Writing

Defining Common Knowledge

Common knowledge refers to information that is widely known and accepted by educated people, or facts that can be found in multiple general reference sources without attribution. This type of information typically doesn't require citation because it's considered part of the shared knowledge base of an academic community. However, determining what constitutes common knowledge can be more complex than it initially appears, and the boundaries shift depending on your audience, academic discipline, and the specificity of the information.

The Two Levels of Common Knowledge

The concept of common knowledge operates on two distinct levels. General common knowledge encompasses facts that most educated people would recognize, such as major historical events, basic scientific principles, and widely known geographic information. This type of knowledge transcends academic disciplines and represents information that appears consistently across general reference sources without specific attribution to individual researchers or authors.

Field-specific common knowledge, on the other hand, represents information that is well-known within a particular academic discipline or professional community but might be unfamiliar to general audiences. For example, in psychology courses, it's common knowledge that Freud developed psychoanalytic theory, but the specific details of his theoretical framework would require citation. Understanding this distinction is crucial for academic writing, as what counts as common knowledge changes depending on your intended audience and the context of your writing.

The Multiple Sources Test

The "multiple sources" test provides a practical approach to identifying common knowledge. If you can find the same information presented in five or more general reference sources without citations to specific researchers or original studies, it's likely common knowledge. However, this test has limitations, particularly when dealing with recent discoveries, statistical data, or specialized information that might appear in multiple sources but still originates from specific research studies.

When to Cite Despite Common Knowledge

When uncertainty arises about whether information constitutes common knowledge, the safest approach is to provide a citation. Over-citing is rarely problematic in academic contexts, while under-citing can lead to plagiarism accusations. This conservative approach demonstrates academic integrity and helps readers trace the sources of information, which enhances the credibility and transparency of your work. To verify proper attribution boundaries, use a attribution checker.

Understanding what constitutes common knowledge through concrete examples helps you make better citation decisions. These examples represent information that most educated readers would consider common knowledge and typically don't require citation.

Historical Facts That Are Common Knowledge

Major historical events and widely known dates fall into the common knowledge category:

• World War II ended in 1945
• The United States declared independence in 1776
• Shakespeare wrote "Romeo and Juliet"
• The Berlin Wall fell in 1989
• The Renaissance occurred in Europe from roughly the 14th to 17th centuries

Scientific Facts and Natural Laws

Basic scientific principles that appear in general textbooks and reference materials:

• Water boils at 100°C (212°F) at sea level
• The human body has 206 bones
• DNA contains genetic information
• Gravity causes objects to fall toward Earth
• The speed of light is approximately 299,792,458 meters per second

Geographic Information

Basic geographic facts that appear in atlases and general reference works:

• Paris is the capital of France
• The Pacific Ocean is the largest ocean
• Mount Everest is the world's highest mountain
• The Nile is often considered the longest river
• Australia is both a country and a continent

Even if information seems widely known, certain circumstances require citation. Understanding these distinctions will enhance your academic credibility and help you understand plagiarism fundamentals:

What counts as common knowledge varies by academic discipline. Information that's common knowledge in one field may require citation in another: