It also might be advice for timed tests—even if the probability of the getting the question right increases after being scrutinized more closely, doing that before answering all the questions might not be the strategy with the highest expected score—if the increase in time taken doesn’t result in an increase in expected score greater than answering an additional question, then opportunity cost may be too high.*
*This may rely on all questions having equal value.
It also might be advice for timed tests—even if the probability of the getting the question right increases after being scrutinized more closely, doing that before answering all the questions might not be the strategy with the highest expected score—if the increase in time taken doesn’t result in an increase in expected score greater than answering an additional question, then opportunity cost may be too high.*
*This may rely on all questions having equal value.