Understanding their background knowledge and previous learning prevents needless repetition or insufficient explanation. (ascd.org)
It only brings needless repetition, and if you enjoy grinding same boss over and over and over and over and ooooooover and over and over again, then maybe this is the best thing. (metacritic.com)
Use short paragraphs (four sentences max) and short sentences, and avoid needless repetition. (creativeboom.com)