In the performance of the audit which leads to an opinion, the independent auditor holds himself out as one who is proficient in accounting and auditing. The attainment of that proficiency begins with the auditor's formal education and extends into his subsequent experience. The independent auditor must undergo training adequate to meet the requirements of a professional. This training must be adequate in technical scope and should include a commensurate measure of general education. The junior assistant, just entering upon an auditing career, must obtain his professional experience with the proper supervision and review of his work by a more experienced superior. The nature and extent of supervision and review must necessarily reflect wide variances in practice. The auditor charged with final responsibility for the engagement must exercise a seasoned judgment in the varying degrees of his supervision and review of the work done and judgment exercised by his subordinates, who in turn must meet the responsibility attaching to the varying gradations and functions of their work.