a model used to evaluate the extent of open and authentic communication between individuals. It is an imaginary window with four panes that each represent a dimension of knowledge about a person: (a) The open pane contains information about the person that is known both to the person and to others, (b) the blind pane contains information about the person that is known only to others, (c) the hidden pane contains information about the person that is known only to the person, and (d) the unknown pane contains information about the person that is known neither to the person nor to others. The goal is to increase the amount of information about the self that is known both to the self and to others. [devised in the 1950s by U.S. psychologist Joseph Luft and U.S. psychiatrist Harrington V. Ingham]