Dependence vs dependency

So I have been writing up a lot of work recently. The subject is stellar winds (like the solar wind) and stellar rotation. I quite often use the word ‘dependence’. For example, I might write something like this

“The speed of the solar wind has a dependence on the magnetic field.”

Somebody suggested recently that I am using the word ‘dependence’ wrong and I should instead be using the word ‘dependency’. After thinking about it for a short time, I have to say, I have no idea what the correct word is here. Does anybody know? My impression is that my above example is correct. I feel like the word ‘dependency’ is something you get if you take drugs too much or something.

(also, I would write the above example as “the speed of the solar wind depends on the magnetic field”, but this is just an example sentence)

Dependence does not have a plural form, whereas dependency has a plural form, dependencies. I wonder if this difference is related to a difference in meaning between the two words. Is dependency a less abstract concept than dependence (which is only used as an uncountable noun)?


Is it only used in scientific journals?

Ok, this is a bit complicated. If you look at your link, it says ‘dependence’ is uncountable, so should have no plural form. On the other hand, look at the page for dependency

None of the definitions match what I am trying to say with the word ‘dependences’. I have just done a search of the ADS (NASA/ADS), which is what astronomers use for finding astronomy literature. I looked for papers with dependences and dependencies in the title and found many examples of both.

You might want to address this question to experts in your field, not to a general audience. Technical usage often makes fine distinctions between closely related words that might be used interchangeably in general usage.

You might be right, but this is not about the technical usage of these words. I think the general knowledge of the details of the English language is better here than among the native speakers who I work with.

Dependence, dependency, and power in the global system: a structural and behavioral analysis
by James A. Caporaso
According to this article, dependence, in the field of international relations, is a “generic” term.

  1. Absence of autonomy, or “dependency”
  2. The opposite of Interdependence, or asymmetric form of interdependence

“In statistics, dependence is any statistical relationship between two random variables or two sets of data. Correlation refers to any of a broad class of statistical relationships involving dependence.”
"Formally, dependence refers to any situation in which random variables do not satisfy a mathematical condition of probabilistic independence. "

“The speed of the solar wind has a dependence on the magnetic field.”

You can argue about the dependence of the speed of solar winds on the magnetic field.
(I simply wrote the above sentence to practice writing in English.)

“Copper’s resistivity dependence on temperature is known to me, can that be used to derive the mean free path dependence in the following way?”

The dependence of copper resistivity on temperature. In this phrase, dependence is not plural.
I wonder if you can talk about some dependences of copper resistivity on temperature. Or would you talk about the dependencies of copper resistivity on temperature?

Thanks for all the posts. I have been looking into it and I think ‘dependences’ is probably the best to use. I think that both ‘dependences’ and ‘dependencies’ are used in the scientific literature because nobody knows what the correct answer is, if indeed there is a correct answer. Most people simply don’t pay attention to these things.

Or…“Solar wind speed depends on magnetic field strength”…

Or, solar wind speed is effected/determined by magnetic field strength.

Or…oh, never mind:)

effected or affected?

Dunno, it was 3 am:) Still can’t think straight, lol
Grammatically, it should be ‘affected’, since magnetic field strength impacts on solar wind speed. And that’s the one I’d always go for.

However, at 3 am…I wondered, grammar considerations aside, whether the dependency was so strong that magnetic field strength in fact executed, ‘effected’, solar wind speed altogether! But nah, 2 coffees later, it’s best to go with ‘affected’:slight_smile: Hey, maybe I should have typed “æffect” ! ^^


…also, it’s the “solaя wiиd”

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I’d use the two words interchangeably. Your field apparently does not. That’s my point.

For what it’s worth… or ‘solar wind speed is dependant on magnetic field strength’?

They seem to use them interchangebly, but probably for very little reason. It is unclear to me if this is grammatically correct. They are science nerds, not language nerds.