Currently I am working on a sociology assignment. Can I write A:=B (A is defined as B) in this assignment? Is this notation general in humanity assignments?

In STEM assignments, I frequently use ":=" to define things: for instance, "Pr:=probability" or "A_{i,j}:= ith resident is j years old".

  • I would guess that "=" is enough and more common.
    – Buffy
    Commented Sep 17, 2021 at 14:23
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    Explain your notation. I think that "=" notation is evil, and a very bad practice introduced by C programming, because that equality notation confounds definition or even variable overwriting with equality established through proofs, or equality being checked for validity. Other people use a different explicit notation for definition, but as long as you introduce it, I think it is fine. ":=" is a nice notation. Commented Sep 17, 2021 at 14:41
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    What is commonly used in the literature? Using new, non-standard notation is not going to make it easy to get your point across.
    – Jon Custer
    Commented Sep 17, 2021 at 15:23
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    For what it's worth, your A_{i,j} example strikes me as awkward from a STEM perspective. How is it supposed to be read? "A_{i,j} is defined as ith resident is j years old"? Would probably flow better if written out as a sentence using 'denotes' instead.
    – Anyon
    Commented Sep 18, 2021 at 15:48
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    It's a course assignment? (You tagged it homework.) The person you should be asking is the person who will evaluate it. I can't assign a grade to the assignment, so my opinion is pretty much value free.
    – Dan
    Commented Jan 26, 2022 at 20:33

1 Answer 1


If you want to use a notation that isn't common in that field, then you need to define it at first use. There is nothing wrong with the notation, but you can't assume that a reader will know that you mean it as a "defining" relationship rather than something else.

Moreover, in a non-technical paper, if you are only going to use such a notation a small number of times, it might be better to avoid it altogether and just use natural language to express your intent.

Note also that ":=" isn't universally used for a definition even in STEM fields. For example, in some programming languages it is used for a variable assignment and a reassignment may be permitted, depending on the language.

Even mathematicians define any new (to the field) notations.

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