This paper demonstrates through the use of two case studies from a regional assessment center in Northern Ireland a method of measuring how adolescents see themselves in relation to various significant people in their environment. Making use of personal ways of judging others, this method is sensitive to relatively small changes in how the subjects perceive themselves with respect to others and is thus valuable for measuring aspects such as the effects of residential treatment, type of therapy, and peer relations. The subjects completed a 12 element by 12 constuct ranked repertory grid. The elements consisted of various title roles, such as 'myself as others see me,' 'my mother,' 'my father,' a 'liked teacher,' and a 'disliked teacher,' for which the subjects were asked to identify a person who fit the title. The first case involved a disturbed, withdrawn adolescent boy with verbal communication difficulties, while the second case concerned a delinquent of below average intelligence and poor reading skills. Clinical and behavioral information is given in order to show how the interpretation of the self-identity plots can be validated in terms of behavioral correlates. In both cases, the self-identity plot interpretation proved to be valuable tool, both in individual diagnostic assessment and as a method of measuring personal psychological change over a period of time or as a result of therapeutic intervention. Four figures and eight references are given.