본 연구에 앞서 여러 가지 약물에 대한 실험을 통해 알약에 새겨진 글자의 인식률이 주변 환경에 크게 좌우되는 것으로 나타났다.
In a test conducted on various drugs prior to this study, it was found that the recognition rate of letters engraved on pills was highly dependent on the surrounding environment.