Schools often tend to either use mixed ability teaching or sets. There are advantages and drawbacks to each type. I’m going to try to explain the logic in both.
Schools are under huge timetable constraints with such a range of subjects and many other things going on. To put a school under even more strain to split the children into various sets would cause a lot of problems. Therefore, from a timetabling prospective mixed ability groups are a better option. The problem with mixed ability groups is that the teacher often pitches the lesson at the children in the middle of the group. So, the higher ability children tend to lose out and the lower ability children often can’t understand the lesson. Some teachers say that it makes the room more competitive, but I think it is far from ideal.
Sets are better, because it allows the teacher to target the level to the ability level of the child. This means that the group makes a lot more progress. However, it often causes time table problems with the school. Also, parents always want their child in the top set. Top sets are often taught more advanced work at a faster pace, whilst the bottom sets are taught the work at a slower pace. The lower ability children are often given colouring in to do.
In both cases the teacher should provide differentiation to cater for the needs of all children. There are several ways that differentiation can occur. Differentiation by outcome is where the children are all set a task e.g. a worksheet. As they work through the worksheet, the questions become harder. So this will provide a level of differentiation and it is what most teachers will use. The alternative is differentiation by task, this is where the teacher gives the students different tasks to do. The lower ability children will have an easier task than the higher ability children. This is more problematic to use in the classroom as it makes it difficult to go through the work as a group afterwards. However, differentiation is the key to targetting childrens levels effectively. I often use differentiation in my group teaching and when I tutor children on a 1 to 1 basis.