If something appears small, but is actually large...is it said to be deceptively small or deceptively large?

The former.

Ditto. It’s deceptively small, but in reality larger. Just remember that deceiving is looking like something it isn’t. So think of which it is and the other is what you put after “deceptively.”
Examples:
If someone is short, but looks tall: Deceptively tall.
If someone is smart, but seems stupid: Deceptively stupid.
And so on…

My friends and I were debating this. My answer was that it depends on context. It IS deceptively large, but LOOKS deceptively small. Doesn’t that make sense? They’re adamant about their answers though.

Wait a minute… Wouldn’t you put the actual word that it is? Deceptively is an adverb that describes the action (of being small), bit doesn’t necessarily reverse its meaning. Could you replace it with “sneakily”?

OR with “surprisingly”?

@Nimis – That makes sense to me. When I searched the phrase “deceptively large”, many real estate ads popped up on Google, which indicates to me that something that seems small is, in fact, “deceptively large”. Who would want to admit that a property is actually smaller than it looks?

If something is deceptively simple, isn’t it seemingly complex but actually simple?

I honestly never thought about this stuff. Good question.

Oooooooh a link. Apparently, it can be either, due to such confusion.

Ah! But it also says that the easiest remedy is to rewrite the sentence without “deceptively”...so our original logic works! (good example with the real estate too).
If an object looks small, but is large—> It looks (deceptively) small and is (deceptively) large.

This question was deceptively difficult.

Deceptively large.

You’re saying the item is large and you didn’t expect it to be. The adjective “deceptively” doesn’t change the fact that you’re describing this item as large- not small.

Some people are confusing the issue by saying it LOOKS deceptively small, but IS deceptively large. It can’t be doubly deceptive- it either LOOKS small, but is deceptively large- or it looks large, but is deceptively small.

Jballou: But I can use your own logic against your argument. The adverb (not adjective) doesn’t change the actual verb. The verb can either be LOOK or IS. I think that is where people get confused, whether to apply the adverb (deceptively) to its appearance or its actual state of being.

It can be doubly-deceptive—in appearance and then in its actual state of being.

If you substitute “surprisingly”, it might be less…confusing?
If an object LOOKS small, but IS large.
The object LOOKS surprisingly small, but IS surprisingly large.

Jballou: Nevermind, I see what you are saying. You wouldn’t use deceptively twice at once.

Jbalou: Actually, I take that back. All of the following statements can be true.
It LOOKS deceptively small, but IS large.
It LOOKS small, but IS deceptively large.
It LOOKS deceptively small, but IS deceptively large.

The only reason why your logic would work is that people naturally focus on a singular deception in their statement.

I guess that makes the “but” inappropriate?
It LOOKS deceptively small and IS deceptively large?

Who’s on first.

What’s on second.

I Don’t Know’s on third.

You’re totally right, “deceptively” is acting as an adverb, and is describing the verb, not the object. So it can both LOOK deceptively small and BE deceptively large at the same time, because the object itself isn’t deceptive.

It’s deceptively small looking.

Aha! Further obfuscation and confusion. This is a deceptively simple question.