The model assumes such and such.

The hypothesis assumes such and such.

In scientific writing, I commonly see similar phrases indicating the construction or use of a model with an assumption. It is so common that it seems to me practically accepted, yet this guide points out that a model cannot assume anything.

It must be the writer. Similarly, the guide (see under ASSUMES) states that a hypothesis cannot assume anything, it is the author that does so.

For the model to be able to assume sounds to me to create a "personification" of the model, which is a valid literary device. While generally to be avoided, perhaps this is an acceptable style even if aiming to write well? One could plead that otherwise the sentences could become much longer and clunkier if every time we had to note that it was the authors who assumes in the use of construction of the model such and such.

Is such personification acceptable or would it be considered poor form?


Since there seem to be answers advocating both ways, perhaps this APA guideline can help us push a little deeper. It seems to say do not use anthropomorphisms in technical writing, except "when they make sense."

Remember that anthropomorphism is about whether it makes sense for that object to take that action. Theories, models, tables, data, results, etc., can take some actions that make sense for these nouns.

Theories, results, and so on, can show, present, or indicate (see APA, 2010, p. 69):

  • The results showed a relationship between time spent in the intervention program and student standardized test scores.
  • The table presents information on the demographics of this study.
  • These data demonstrated that increasing awareness of diabetes indicators can help patients reduce their risk of being diagnosed.
  • The theory indicates that societies work much like ecological systems, with different groups playing different and necessary roles in the larger system.

For me, this confuses the situation, given that whether it makes sense for that object to take that action sounds slippery. I can see how one could be very lenient or not in dispatching their judgment. For model and hypothesis, it does clearly state that these words are acceptable exceptions that "make sense." Do you have any better guidance?

  • 3
    The usage is familiar and nonconfusing, though a pedant can complain about it. It's a matter of taste whether that makes it right or wrong. Dec 16, 2019 at 2:51

2 Answers 2


The link you cite is rather ungenerous in its criticism:

ASSUME — An active verb often used with an inanimate subject to produce a ludicrous statement (The hypothesis "assumes" that .. or The model "assumes" ...) Models or hypotheses cannot assume anything! However, to use a model or to test a hypothesis certain assumptions often are required; the person who uses the model or tests the hypothesis must make the assumptions.

This would appear to be a somewhat histrionic display of one writer's pet peeve. As such, it is not necessarily felt by others. For example, The American Heritage Dictionary gives the following as its first definition for assume:

  1. To take for granted; suppose: The study assumes that prices will rise.

One would suppose that if there were anything wrong with attributing assume to an inanimate object, the combined editorial board of a dictionary would have at least mentioned that. Instead they go blithely forward with their pathetic fallacy (which is neither pathetic in the pitiable sense nor a fallacy in the logical sense). And in fact I have read many scientific treatises that use the pathetic fallacy in just that way: "This model assumes A, B, and C." You can think of it as a shorthand way of saying "The authors of the model assume A, B, and C."

It is quite obvious that the suggestion that a model can assume anything is indeed so ludicrous that all the adults in the room will immediately understand that this is just another way of making a statement. And it may even be more precise to attribute the agency to the model in this case, because the authors of it may be comparing it to other models that are predicated on different assumptions. Instead of saying "the authors assume" it could even be more precise to say "these different models assume [certain values or criteria]" because the statement is referring to values that belong to the models themselves, not the authors of them.

That said, if you are in school and submitting work to a professor who gave you that guide as a model to follow, you would be well advised to follow it. And if you are submitting an article for publication, it might also be advisable to seek to determine whether the target publication has a house style that censures a more liberal usage of the verb assume. As noted in Wikipedia's article on the pathetic fallacy:

In science, the term "pathetic fallacy" is used in a pejorative way in order to discourage the kind of figurative speech in descriptions that might not be strictly accurate and clear, and that might communicate a false impression of a natural phenomenon. An example is the metaphorical phrase "Nature abhors a vacuum", which contains the suggestion that nature is capable of abhorring something. There are more accurate and scientific ways to describe nature and vacuums.

It seems to me that this sort of figurative speech is a long way away from simply saying that a model assumes something, which is hardly poetic but certainly well understood. Still, there is no accounting for prejudice and fussbudgetry. In the final analysis it is up to you to determine whether your work will be helped or harmed in the venues you choose to pursue.


You added APA stylesheet information, but that doesn't change my answer. Understand that language is fluid and context-based, and what is acceptable in one instance may be unwelcome in another. With that in mind, note that the two answers to your question don't really disagree. Mine is a little more nuanced, saying you have to understand when you can or can't employ the particular usage of assume.

The burden is still on you to judge your audience. But as you yourself have observed, many treatises show models "assuming" conditions. If you're satisfied that your audience will not raise fussy objections, or that the usage will not cause a distraction, go ahead and let your models assume away. If you're not satisfied with respect to those conditions, find another way to say what you mean. Be aware, however, that no answer on this site will inoculate your prose against criticism, and you will not get to offer it into evidence in the court of your audience's opinion.

  • Thank you, this is a great answer. Just posted a small update to the question, given the other responses. Take a look. Dec 16, 2019 at 15:51

Both sentences in your question look slightly incorrect because of the personification of the words "model" and "hypothesis". Let me explain my point with the second word: an "hypothesis" in mathematics is a list of assumptions under which a conclusion can hold true. An example: "Assuming that $p$ is a prime number $>2$, we obtain that $p$ is odd".

As a result, the hypothesis itself does not assume anything. You could replace the word hypothesis by assumption and say "The assumption (or the hypothesis) is that $p$ is a prime number $>2$", or "We assume that $p$ is a prime number $>2$" or "our hypothesis is that $p$ is a prime number $>2$", but to say that "our hypothesis assumes that $p$ is a prime number $>2$" is a weird personification of the word hypothesis and is in fine incorrect and misleading.

  • Thank you for your answer. Just posted a small update to the question, given the other responses. Take a look. Dec 16, 2019 at 15:51
  • I think that the personification referred to above could be in fact misleading. Strictly speaking "The hypothesis assumes" is a nonsense and it is also some type of misunderstanding: we have made an hypothesis with such and such statement and that assumption will help us to prove our conclusion. Dealing with somebody telling me that expression would put me on guard of having to deal with an individual ignoring what means an assumption versus a conclusion. That personification has a weird content which is on the border of incomprehension and naivety.
    – Bazin
    Dec 16, 2019 at 21:02

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.