Mark Sense card

Mark Sense, or elecrographic, technology is used to allow data filled out by end-users to be tabulated through electrically-sensed marks on the card, similar to punched cards except that instead of being entirely punched out, the marks are made with particular kinds of pencils which use elecrically-conductive lead so that the marks can be read. (Sometimes they were read by keypunch machines which automatically punched the marked spots, allowing the cards to be read by punched-card readers afterward.) This system was used for test answer sheets in many instances from the 1930s to the 1960s, as well as other uses such as meter readings, before being superceded by optical mark recognition which reads the marks optically. The latter is sometimes referred to as "mark sense" as well, though this term officially refers to the electrically-read variety. The end user filling out answers by pencil in little ovals or rectangles doesn't necessarily know or care whether the eventual tabulation will be done elecrically or optically.

Cards or forms filled out this way can be read by humans as well as machines, if it is known what the meanings of particular spots on the form are (which is sometimes included on the form in the manner of titles and legends).