Revision

In IMM, revision after the practice helps the learner to revise the part which they have not understood. The practice is after each part is over. when the learner cannot understand the part revision is taken of the same part. The learner can revise and give the practice test again.
For example, 

this frame is from the package which is about 'Introducing Myself' the practice test will help the learner to know if they have learned to introduce themselves to others. if the answers which the learner has given are wrong he/she can click on the "NEXT" button to get the revision.

This is a revision frame that the learner will get for revision. He/she can play the videos and revise the learning. after the revision they can give the revision test again to know their level.

Hence, revision is an important characteristic of an IMM package as it helps the learner to revise their learning and understand the concept with more clearance.