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Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.

Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com
under the wrong assumption
Grammar usage guide and real-world examplesUSAGE SUMMARY
The phrase "under the wrong assumption" is correct and usable in written English.
It can be used when discussing a situation where someone has made a mistake based on incorrect beliefs or information. Example: "She acted under the wrong assumption that the meeting was scheduled for Friday instead of Thursday."
✓ Grammatically correct
News & Media
Science
Academia
Alternative expressions(19)
laboring under a misapprehension
under a false impression
under the illusion
misled into believing
laboring under a misconception
mistakenly believing
under the illusion that
in the mistaken belief
under a false assumption
regrettably mistaken
unfortunately mistaken
seriously misguided
painfully mistaken
woefully mistaken
sadly mistaken
mistaken
sorely mistaken
tragically mistaken
wide of the mark
Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Human-verified examples from authoritative sources
Exact Expressions
1 human-written examples
"We've spent too much time under the wrong assumption -- two-stock management," he said.
News & Media
Human-verified similar examples from authoritative sources
Similar Expressions
59 human-written examples
Hello, YouTube: this is the wrong assumption.
News & Media
"Where did we make the wrong assumption?
News & Media
Make the wrong assumption and you will fail the case, losing precious intuition points.
News & Media
So the phrase 'barking up the wrong tree' means making the wrong assumption when trying to achieve something.
News & Media
The bill makes the wrong assumption that all startups raise angel or venture capital.
News & Media
This misconception is based on the wrong assumption that ROS fulfill no physiological function.
Mr. Zimmerman, a gun on his hip, made the wrong assumptions and the wrong choices, he said.
News & Media
"Information Literacy Makes All the Wrong Assumptions". Chronicle of Higher Education, Jan .7. Nunberg, Geoffrey, 2005.
In this study the production and order decisions under the wrong yield assumption are inserted in the profit function with correct yield specification with yield parameters that are identical for both yield models.
Science
If the dropout rate is high, a wrong assumption about the missing data may compromise the validity of statistical inferences.
Science
Expert writing Tips
Best practice
When using "under the wrong assumption", clearly state what the correct assumption should be to avoid ambiguity and ensure clarity.
Common error
Avoid applying "under the wrong assumption" too broadly; specify which aspect of the situation is based on the incorrect assumption to maintain precision.
Source & Trust
84%
Authority and reliability
4.5/5
Expert rating
Real-world application tested
Linguistic Context
The phrase "under the wrong assumption" functions as an adverbial phrase, modifying a verb or clause to indicate the condition or basis for an action or state. As Ludwig indicates, it denotes an action or belief stemming from an incorrect premise.
Frequent in
News & Media
29%
Science
27%
Academia
14%
Less common in
Formal & Business
8%
Wiki
3%
Reference
0%
Ludwig's WRAP-UP
In summary, the phrase "under the wrong assumption" is a grammatically correct and useful expression for indicating that an action or belief is based on an incorrect premise. Ludwig highlights its usage across diverse contexts, including news, science, and academic writing, although it is somewhat uncommon. When using the phrase, it's best to specify what the correct assumption should be for clarity. Related phrases, such as "based on a false premise" or "mistaken in the assumption", can serve as alternatives. Ludwig’s examples demonstrate its versatility, confirming its appropriateness for various writing styles.
More alternative expressions(10)
Phrases that express similar concepts, ordered by semantic similarity:
mistaken in the assumption
Directly points out the error in the assumed belief.
based on a false premise
Emphasizes the incorrect foundation upon which a conclusion or action is based.
laboring under a misapprehension
Highlights a misunderstanding that influences one's actions or beliefs.
with a flawed presupposition
Emphasizes the underlying assumption as the source of the error.
operating on an incorrect belief
Focuses on the erroneous belief that guides one's actions.
with an erroneous hypothesis
Highlights the flawed starting hypothesis that has led to errors.
proceeding from a faulty understanding
Stresses the flawed comprehension that leads to an error.
misled by a false impression
Highlights the deceptive nature of the initial information received.
having an inaccurate perception
Focuses on the distortion of reality influencing actions.
under a delusion
Indicates a belief held despite evidence to the contrary.
FAQs
How can I use "under the wrong assumption" in a sentence?
You can use "under the wrong assumption" to describe a situation where someone makes a mistake because they believe something that is not true. For example, "She acted "based on a false premise" that the meeting was scheduled for Friday instead of Thursday".
What are some alternatives to the phrase "under the wrong assumption"?
Some alternatives include "based on a false premise", "operating on an incorrect belief", or "mistaken in the assumption", depending on the context.
Is it better to say "under a wrong assumption" or "under the wrong assumption"?
"Under the wrong assumption" is the more common and grammatically preferred phrasing. The definite article "the" specifies a particular, often previously mentioned or understood, assumption.
What's the difference between "under the wrong assumption" and "misled by a false impression"?
"Under the wrong assumption" focuses on the internal belief that is incorrect, while "misled by a false impression" emphasizes the external source that caused the incorrect belief. The first focuses on who is wrong, the second why somebody is wrong.
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Table of contents
Usage summary
Human-verified examples
Expert writing tips
Linguistic context
Ludwig's wrap-up
Alternative expressions
FAQs
Source & Trust
84%
Authority and reliability
4.5/5
Expert rating
Real-world application tested