  Any multiplicity-free family of finite dimensional algebras has a canonical
complete set of of pairwise orthogonal primitive idempotents in each level. We
give various methods to compute these idempotents. In the case of symmetric
group algebras over a field of characteristic zero, the set of canonical
idempotents is precisely the set of seminormal idempotents constructed by
Young. As an example, we calculate the canonical idempotents for semisimple
Brauer algebras.
