I think assessing a child is good if you are keeping the whole child in mind. Assessments are good to see where a child's learning process is. There are also assessments to see where children are socially, cognitive, and physically. Children need to be assessed, so you as a teacher can know where to start with their learning process. The assessment are very good if you are wanting to see if the child has a learning disability, because that way you can get them the treatment they need to be able to move forward in their learning. I do think it is good to do an assessment on them as early as possible especially if there are concerns that a teacher or parent might have. My grandson is one of a twin and we just found out he is delayed a little bit not much, but without the help of a "help me grow program, and children's Hospital we would not know that. He was late walking and talking, but with people coming to our house and working with him and their parents it has made a big difference in his learning process. Testing are good but can be over tested and that is one thing you do not want to do. All children learn at a different pace, some children will learn quicker than others, but then some takes them a while to catch on.
I chose to explore England and from exploring there is not a lot of difference in their testing process. They use their testing information to help them to know what to teach, and to share with the parents any concerns they might have with their child's learning. There are observation and collection of the child's work to be able to see where they are learning wise. Which that is one way of doing assessments in the United States.
I just hope that the testing is not something that will scare the children from wanting to learning new things in their learning or education. Testing is good as long as it is not abused. It is good to focus on what is best for each child in their learning and give them a boost to want to learn.