Baltimore, MD. Chances of a mechanical error escaping detection are infinitesimal in the Social Security Board Records Office and great care is excercised to guard against human error. After the employee master card has been prepared, and before it is sent on to reproduce an acturial card, indexes, registers and a individual ledger account. It goes to a review section. Here the original application and the master card are brought together and checked for error. Checking is done by a team of two workers, and the few errors which have been made are corrected. Reviews of errors are reduced to a minute part of one perscent. The photograph above shows a part of the review section at work