The transition dip
In many schools, there is a dip in progress in Year 3. This is most likely to be because children take time to adapt to the different demands of a Key Stage 2 curriculum. Teachers' expectations of what is required to meet the levels also change.
For example, a bright child may achieve a level 3 at the end of Year 2. When that child is still on a level 3 at the end of Year 4, parents are often worried that their child hasn't made any progress.
This worry is generally unnecessary: in order to achieve a level 3 in Year 2, a child has to over-reach the Year 2 expectations.
But in Years 3 and 4, children are taught the whole level 3 curriculum and are assessed against its more demanding standards.
A similar transition dip occurs when children transfer from primary to secondary school.
And again, it is most apparent with high-attaining children who seem not to continue making progress at the same rate as before.