It is necessary
An exception is mass express inspection of children at their selection on a school logopunkt or inspection of graduates of kindergartens, etc.
As a rule, parents ask to settle down at some distance so that the child felt their presence, but did not see them constantly.
It is necessary for the following reasons.
Vopervykh, presence of mother or father inspires the child, does it quieter and surer.
Sometimes he even turns around to see reaction of parents.