One inefficient study method preferred by students is to repeatedly reread sources. It is an example of overlearning and can creates an illusion of progress after the source start to feel familiar. And it is easy to conflate familiarity with understanding.
Employing repeatedly rereading strategy also indicate a fundamental misconception of memory. We like to view memory as an “unreliable camera” (think about Monte Carlo Simulation) which will eventually converge to understanding if we spend enough time rereading,
The correct mental model for our memory is that it actively reconstructs the source base on prior knowledge. To construct our own understanding, we can make questions while reading to force ourselves to think in our own words and draw in prior knowledge. A technique called elaborative interrogation is a great way to formalize this process.