An empirical statement is usually based on (external) empirical research. A source reference is absolutely necessary here.
Example: „The suspect rate among 14- to under 18-year-olds decreased from 7.0 % in 2007 to 5.5 % in 2015“ (Police Crime Statistics, 2015).
If the empirical statement is based on your own observations or research, a source reference is not required, but you should document the research process to allow assessment of its validity. You also do not need sources to mention undisputed statements and general knowledge in your field.

When you make analytical statements based on your own reasoning, a source is not required. For example, you can draw the following conclusion if you previously presented refugee numbers with sources:
Example: „The strongly differing numbers of refugees with secured residence status in Germany and Hungary show that the two countries pursue different goals in their refugee policies.“
However, if you refer to a thesis in the literature, you must prove it with a source. This is always necessary when there are multiple, sometimes conflicting positions.
If you refer to the ideas of other authors and draw your own conclusions from them, you must make it clear where your own thought begins.

Therefore, the often-given advice in guides is not always correct: „Prove everything that does not come from you“.
With a normative statement, you indicate that a behavior or procedure conforms to or should conform to a generally accepted norm. Note: if this statement represents your own opinion, you must justify it. Your reasons should not be based solely on gut feeling.
Example: „In my view, a humane refugee policy should reconsider the distinction between economic refugees and political refugees, because …“.
You can include such statements in the conclusion when you make your own recommendations for action.

What do I need to cite?
Always cite when you adopt formulations or ideas from other texts. Basic knowledge in your own field does not need to be marked as a quote.
How do I cite correctly?
To cite correctly, provide the source both at the exact place in the text and in the bibliography.
This article was published in August 2025 and last updated in March 2025.