As a supervisor you should continue the training until proficiency is achieved. You do not have to continue training indefinitely BUT you should continue monitoring and supervising.
When training a staff member to conduct an intervention you should provide an UNAMIGUOUS(AKA precise) definition of the intervention procedure. ALthough you should observe the trainee complete the intervention procedure, you don't have to have anyone observe them at ALL time.. and having another TRAINEE observe them without supervision can actually be counteractive.
After a staff memebr can competently perform an assessment or intervention precedure, you should continue intermittently monitoring and supervising them on the procedure.
BCBA should only allow staff to independently conduct assessments when they have demonstrated proficiency in the procedure.
Before training staff memebrs on an intervention procedure you should create a precise, complete and unambiguous operational definition of the intervention.
How to competently perform an assessment: modeling the assessment process, providing written directions on how to conduct the assessment.
It is crucial for a BCBA to remember when training staff to competently perform an assessment, BCBA must continue training until proficiency is achieved.