It soon became clear to Ender that even though Dink was very, very good, his persistence in holding onto the corridor gravity orientation instead of thinking of the enemy gate as downward was limiting his thinking.
There are no more uses of "persistence" in the book.
Show samples from other sources
The majority of men meet with failure because of their lack of persistence in creating new plans to take the place of those which fail.
The art of love ... is largely the art of persistence.