optimal and optimum

Discussion in 'English Only' started by prankstare, Sep 6, 2008.

  1. prankstare Senior Member

    São Paulo
    Portuguese - Brazil
    What is the difference between "optimal" and "optimum" ?

    If possible, give some phrasal examples.

    PS: yes, I have tried looking up first before deciding to post this one. Could not find one a thread in one of the languages that I can fairly understand though.
  2. chat9998 Senior Member

    English, US
    Hi prank,

    There really isn't a difference. They both mean the same thing. In fact, dictionary.com defines 'optimal' using 'optimum'. :)
  3. mbr

    mbr New Member

    English - U.S.
    Just to add on to what chat9998 said: both can function as an adjective but only “optimum” can be used as a noun.

    In fact, there are some people who believe that “optimum” should only be used as a noun and it’s only because people have repeatedly used it as an adjective (incorrectly) over a long period of time that it has become acceptable as an adjective.

    So if you want to be safe, it would be best to only use “optimum” as a noun. But I’m sure no one would correct you if you used it as an adjective, especially because all dictionaries I’ve looked at list it as both.
  4. prankstare Senior Member

    São Paulo
    Portuguese - Brazil
    Hey, :)

    I'm still unsure about this. I wonder if there really isn't something more behind the usage of these two words; look, yesterday I was talking to a north American guy and asked him the same question -- he was embarrassed about the fact he couldn't tell the difference. So, I came up with an idea and asked him which of these two words would sound best to him and gave a sentence. The example he was given was the following:

    "That is the optimal/optimum solution I can think of for now"

    And his choice was for the word 'optimum' there -- he said 'optimal' sounds filling, but 'optimum' sounds more expansive, like it rolls off the tongue better. But I think this is just a matter of how the two words will sound in a sentence.
  5. cycloneviv

    cycloneviv Senior Member

    Perth, Western Australia
    English - Australia
    Well, I have a problem with that question because I would definitely not use either word in that context. I would use "best".

    Both optimal and optimum imply to me that whatever is being described is, absolutely, the most efficient/best of its type. Saying it's the optimal/optimum thing I can think of for now just doesn't work, because it implies that there is quite probably a better one but you just can't think of it at this moment. If you've already thought of the optimal solution, it is not possible that you will later think of a better one. There is no better one.

    I hope that makes some sort of sense!
  6. prankstare Senior Member

    São Paulo
    Portuguese - Brazil
    Yeah, thanks everyone that replied.

    Well, this seem to be really intriguing. From now on, I am going to use "optimum" to work only as a noun and use "optimal" whenever referring to as an adjective, just to be safe, as suggested by 'mbr'. :)
  7. prankstare Senior Member

    São Paulo
    Portuguese - Brazil
    OK, I admit being a bit wiser this time and performed a search upon 'minimal' and 'minimum' to find out whether there's any difference in meaning (and also to find out if it has any relation with the actual discussion here, 'optimal vs. optimum').

    Could what 'Lexiphile' said in post no. 5 in this thread explain the issue about the 'optimal vs. optimum' ?
  8. foxfirebrand

    foxfirebrand Senior Member

    The Northern Rockies
    Southern AE greatly modified by a 1st-generation Scottish-American mother, and growing up abroad.
    Optimum tends to be quantitative, and optimal is qualitative-- the first means most and the second means best.

    They aren't really interchangeable.

    "The stereo was cranked to the optimum volume." A little awkward but essentially correct-- you can't use "optimal" here unless you think of one volume level as good and another bad (not just loud and louder).

    "The trax were mixed for optimal effect." Effect here is a quality, not an amount.

    I believe the same differences exist between minimum and minimal.

  9. prankstare Senior Member

    São Paulo
    Portuguese - Brazil

    Feels like I have changed my mind now. :)

    Thank you 'foxfirebrand' for your clarifying post.

    I really had a feeling this was the same situation as the 'minimal vs. minimum' case.
  10. anotherscott New Member

    I think perhaps the distinction is more that "optimum" is absolute and "optimal" is conditional.

    To use your stereo analogy, if the volume goes to 10, the "optimal" level for a given room may be 7, for example (i.e. if it is too loud for that room beyond that point). It is circumstance-based.

    Similarly, I would use "optimal" in a sentence like, "It is impossible to come up with a recommendation that will be optimal for everyone" (i.e. because everyone's circumstance is different).

    On the other hand, I think "optimum" conveys more of a sense of an ideal or best regardless of circumstances.

    However, I don't think "optimum" is necessarily quantitative.

    So to go back to your stereo analogy, if the sound of the stereo significantly distorts when you turn the volume past 8 (regardless of the room), I think I might say that the optimum volume setting for the stereo is 8, even though it goes to 10. "Optimum," then, is still "best," not "most."

    I guess what I'm saying is that I consider both words to generally be qualititave, they both mean "best," but one is an absolute judgment and the other is relative to circumstance.

    That said, I can also see where "optimum" can have a quantitative sense to it that "optimal" lacks. In a sentence like, "Squeeze the orange hard to get the optimum amount of juice out of it," the implication is, we are trying to get as much out of it as we possibly can. Whereas, if someone said they were trying to squeeze it enough to get the "optimal" amount of juice, I think that would imply that there is some amount less than the maximum amount that would be preferable to getting all of it.
    Last edited: Aug 21, 2009
  11. DancePeaceLove123 New Member

    Actually, optimal would be correct in that usage. Mbr is correct in saying that optimum is a noun. Optimal is an adjective.
  12. hanksname New Member

    Southern American English!
    Minimal vs minimum is a little easier to dissect because the words are used more often perhaps. I use minimal as in, "...keeping errors minimal." I would use minimum as in, "...keeping errors to a minimum amount." I see optimal/optimum as the same situation. Optimum is specific amount and optimal is more of a qualitative, non-specific, perhaps non-conclusive adjective. Good topic though, google is great for these little questions that make me wonder every now and then (as opposed to every now and again, you can google that one too!)
  13. anw1652 New Member

    To all of the above, I will also add that my personal experience in the use of either term is that it carries the implication of a condition that is based upon the reconciliation of conflicting requirements or goals, not that it is a perfect synonym for "best". For example, one would say, "The best juice drink is a combination of pineapple and orange juice", and one would also say, "I love pineapple juice, but it costs more than orange juice; for my taste and budget, the optimal juice drink is 1/3 pineapple juice and 2/3 orange juice".

    This is just my personal experience (with my perverse engineering colleagues). I have not found it documented anywhere.

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