However, it is a DI principle that all errors are corrected immediately. That would be true if all the students in a classroom were grouped together. DI programs don't do this. Students are given placement tests and are placed in appropriate groups. Faster students may also be moved to an accelerated lesson or program.
Some people feel that it derives from a failure to understand how the programs are put together.
The students appear to be parroting, especially when the teacher must perform several error corrections. However, a closer look at the way the material evolves from lesson to lesson reveals a very different picture. This is appropriately called rote learning. Still later, the student is capable of sounding many regular words that she or he has never before practiced. But I'm Still Not Convinced.