A proposed man-machine system for encoding fingerprint ridge characteristics is described. The fundamental concept underlying the proposed system is to use an operator to recognize the ridge characteristics and to impart to a computer the ability to manipulate and compare the digitized locations and directions of these characteristics for single-fingerprint classification. The proposed system and encoding schemes were simulated using a RAND tablet and an IBM 1800 computer. Sample input prints were encoded and stored on a magnetic tape. Experimental results on human factors and multiple-impression file searches illustrate the feasibility of computer-assisted fingerprint encoding and classification.