I am seriously peeved by people who say that I can’t compare apples and oranges. They are both fruit, dammit. They both grow on trees. They have comparable contents (i.e. vitamins, carbohydrates, fiber, and so on) and grow to comparable sizes. So puh-leez don’t tell me that apples and oranges can’t be compared. They are prime candidates for comparison.
Confusing apples with oranges would be a mistake, and you would be justified in correcting anyone who did that.
Get it right!
So…what sparked this rant?
Oranges are citrus. Apples are not.
Anyway, it’s a long established and well recognised phrase that is extremely convenient, and handily accurate, when used correctly.
It’s been bothering me for about 25 years. The professor who drove me out of grad school used the phrase frequently.
Thanx to the Straight Dope for giving me the opportunity to vent.
So we can do some contrasting along with the comparing.
I’ll rephrase my thesis: there is nothing wrong with comparing apples and oranges. Confusing apples and oranges is an error deserving of correction.
My physics professor in high school would say that a lot. For example, a student would come up with the answer to a problem, but forget the units. The prof would say “Is that 5.6 apples or 5.6 oranges?”
And of course, he would say that “apples and oranges can’t be compared” when somebody tried to equate things with different units.
And you know what? He was 100% right. Maybe you failed grad school because you mixed up the units!
He’s conflicted about his sexuality.
So if you ask for oranges at the fruit stand, and they give you apples, you don’t mind?
Um…okay. 
Both taste like chicken
Any two things will have some qualities in common to some degree.
He would’ve been more correct to say that “apples and oranges are not interchangeable.”
If I’m not mistaken that *IS * what your hated phrase means.
I also dislike the “apples and oranges” thing. I’ve usually heard it as “you can’t add apples and oranges”. I know what is meant. If you are asked, how much is 3 thousand plus 4 dozen, the answer is not 7. But it’s a bad way of putting it, because both statements are wrong.
First, you can add apples and oranges. If you have 2 oranges and 3 apples, you have 5 fruits. For that matter, you can add all sorts of things more different than two kinds of fruit. If you have 2 can openers and 3 living room sofas, you can say that that adds up to 5 objects. If you have two chickens and 3 doorknobs, you can say that that adds up to 5 things.
Second, you can add thousands and dozens. The reason that 3 thousand plus 4 dozen does not equal 7 is not that “you can’t add thousands and dozens,” because you can can add the two numbers. You just don’t do it the way the person saying 7 did. It’s not that you actually can’t add thousands and dozens, it’s just that you need to learn the correct method of doing so.
I’m not certain to whom this question is addressed, but I’d mind. The vendor is confusing apples with oranges.
Well, if that’s what is meant than that’s what should be said.
But there is no comparision. Apples are clearly superior!
Very well. I move that we change the phrase to “you cannot equate apples and oranges”. Or is that “apples to oranges?”
I really think this is a grocery shopping analogy. If you’re planning to make apple pie, you don’t say “None of these apples looks very good but the oranges are perfect so I’ll use one of them instead”. You simply pick the best apple out of the bunch. The oranges may be of a better quality, but that’s completely irrelevant as you can’t use the orange instead of the apple. It would be like going to the hardware store and opting to buy a hammer instead of a screwdriver because it’s of better quality and value - if you need a screwdriver, then a hammer isn’t going to suffice. You might buy both, but you can’t chose to take the hammer instead of the screwdriver because it’s not able to do what you want it to do. You just have to check out the screwdrivers and chose the one that represents the best quality and/or value in the range.
I thought it might be helpful to include an actual comparison of apples and oranges, done by Scott A. Sandford of the NASA Ames Research Center.
Sandford’s conclusion:
“Not only was this comparison easy to make, but it is apparent from the figure that apples and oranges are very similar. Thus, it would appear that the comparing apples and oranges defense should no longer be considered valid.”