A method and system is presented for the creation, delivery, processing, and overall management of surveys across and on sites and applications that display online and mobile content that is tracked using an audience validation system. Moreover, the digital data recordingreproducing method increases correction capability against several bytes to several tens bytes of errors generated at random without changing burst error correction length by performing this processing for respective PI codes by using interleave rules that are different as much as possible from one another. The lever-mounting plate provided with the mating unit can be mounted to the holding plate through one-touch operation, whereby mounting becomes simple and manufacturing processes are easily automated.