[Grammar] that ~ is more … than this ---

[kaz18]

I'm teaching English in Japan.
One of my students wrote, "This movie is more interesting than that".
I'm not sure this sentence is grammatically correct or not. Don't we also need "movie" or "one" after "that", like "This movie is more interesting than that movie/one"? In the sentence the student gave me, she used "This" as an adjective, and "that" as a noun. A teacher in Canada, where i studied for a year, told me that I should use the word "one" or the noun i want to compare to counterpart when i use this and that in the same sentence.
Someone, familiar to the English grammar, please tell me "This movie is more interesting than that." is acceptable or not, grammatical or ungrammatical?

Could you get what I'm asking here?

 

[Barb_D]

It can work in the context when we know what "that" refers to.

The critics say this movie is about as interesting as watching paint dry. I can tell you, this movie was more interesting than that... but not by much.

 

[kaz18]

Thanks for your quick reply. Your answer helped me a lot:-D

 

[Khosro]

In such cases a dictionary could help. "That" could be a pronoun.