I learned an interesting reading trick from my current mentor, Ms. Massey. When I read, I tend to focus on the how and the why. I attribute that to me being philosophical in how I think. Philosophy was my major and I still continue to think and ask questions in a philosophical way. But, how and why questions within a school text often require self-reflection. On the other hand, what questions can often be answered by looking straight in the text.
This is what Ms. Massey will do. She will be reading a paragraph aloud. Right before she reaches the last word, she will ask them to basically fill in the blank. So, for example, "The Chumash Indians used washed up planks to make.... what did the Chumash Indians use washed up planks to make?" She will either call on a student who had raised their hand or she will just call on a student.
In the case that she calls on a student who raises their hand, she will only be able to determine who was paying attention (on the assumption that the student who had raised their hand knows the answer to the question she had asked... In which case, that would show that that student wasn't paying attention to the reading). In the case that she just calls on a student at random, if that student answers correctly, it seems likely that that student has been following along in the reading. We're assuming that the student is getting the answer straight from the text and the answer is difficult enough that he or she cannot just guess. If that student doesn't answer correctly, then it seems likely that that student was not following along while the teacher was reading. It's possible that the student was following on in the reading but was just confused with how to answer. But, when all they need to do is fill in the blank, there doesn't seem to be much room for confusion as far as providing an answer is concerned.