Hi Larry,
Though simply put this is often harder to do than we think. We must make sure that in assessing the individual student needs we are using an instrument that measuring the true learning needs of the students. Then we must adapt, modify, or create materials that are suitable for the students. This is true even if we are using a standardized curriculum. We have to make it our own, so the students will make it their own. This is the challenge we face each and every day we teach.
Gary