For use in connection with evaluating prosthetic sockets (and other objects) designed and fabricated with computer aided design and manufacturing software, the shape of a socket is accurately scanned and digitized. The scanned data are then compared to either an electronic shape data file, or to the shape of another socket, a positive model of a residual limb (or socket), or a residual limb. Differences detected during the comparison can then be applied to revise the design or fabrication of the socket, to more accurately achieve a desired shape that properly fits the residual limb of a patient and can be used to solve the inverse problem by correcting for observed errors of a specific fabricator before a socket is produced. The digitizing process is implemented using a stylus ball that contacts a surface of the socket to produce data indicating the three-dimensional shape of the socket.