I'm not sure if this might be a math question, but are the following phrases equivalent, or do they differ in nuance:

"Students are tall, on average"

"The/An average student is tall"

I found these questions examining the "an"/"the" nuance: " 'an' vs 'the' average of..." & " 'the' vs 'an' average person". But that doesn't transfer to "the/an" vs "on".

This one ('an' vs 'on' average) seemed similar, but something didn't quite sound right, to me, about the way those two statements were phrased; and there weren't any explanations; just suggested rephrasings.


  • What are the blanks? They aren't for "on/the" but they don't seem to be equivalent parts of speech.
    – Jim
    Apr 24, 2019 at 4:24
  • Sorry, I meant for them to mean [some arbitrary grouping of people]. Ex: men, women, Americans, teens, etc. I updated the text.
    – Yurelle
    Apr 25, 2019 at 18:02
  • (1) Students are tall, on average. (2) The average student is tall. Is that a fair translation? (I can't fully understand what you're asking without definitive examples.) If that is what you're asking, then the two sentences have subtly different meanings (although they may have the same practical result) . . . Apr 26, 2019 at 1:25
  • Yes, that's what I meant. Sorry, for some reason I thought the gibberish was simpler. I've changed it to your translation.
    – Yurelle
    Apr 26, 2019 at 3:34

2 Answers 2


Both expressions are used when speaking about groups of entities. The difference is that "On average" refers to the characteristics of the the group as a whole while "An average" or "The average" refers to a typical, representative, member of the group.

If we say that "On average students spend 20 hours per week in the Union bar and 15 hours per week in the university library" we are suggesting that if we were to log the times spent by all members of the student body in those places and calculate means, medians or modes for the group (depending on our choice of methodology) then 20 hours and 15 hours would be the result. There would, of course, be some students who spent more time in each place and some who spent less; there might even be some who never went to the bar, some who never visited the library and some, possibly, who never went to either but the average would be what we suggested.

If we say "The average student spends 20 hours per week in the Union bar and 15 hours per week in the university library" this suggests that we can find at least one student who spends exactly those amounts of time in those places. By implication, though, it suggests that we can find many of them, perhaps even a majority who do that. We are also suggesting that students who spend much more time in one of the places and/or much less in the other are, somehow, not typical members of the group.

Saying "The (or an) average..." carries a strong suggestion that a member of the group with the specified charateristic is typical of the group than "On average...". In statistical terms "The average..." suggests the existence of a mode for the dataset which fits the characteristic of a large majority of the members of the group where "On average..." carries no such suggestion.


I believe it's the same thing. 'The average person....' forms a basic (average) person in the readers mind doing/in xyz. 'On average' is just a more general use.

  • "On average" can be replaced with "usually". The average implies that a computation (mean, medium, mode) was performed. Or at least a request to see that data would be my next question. Much depends on context and I, come to think of it, may not be "average". Apr 25, 2019 at 20:16

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