I have a question. When using the word at in a sentence I am either confusing myself or overthinking the word? In this sentence, "During the actual observation, what her focus is on and what key items she looks at." have I used at incorrectly? I keep thinking that the word at signifies a specific location, but I don't know and so here I am asking.
"To look at" means "to observe," so she was looking AT whatever her focus was on.
The phrase is not a sentence, however, so that may be contributing to your feeling that there's something wrong.
During the actual observation, the researchers keep careful notes of what her focus is on and what key items she looks at.