Nurse researchers have become increasingly concerned with the development, testing and continued refinement of reliable and valid instruments which can index phenomena of interest to nursing. A primary step in the measurement of such phenomena is the systematic initiation of conceptualization processes which yield adequate construct definitions. Adequate construct definitions facilitate efforts toward precise measurement. Presented in this article is a description of how grounded theory methodology guided conceptualization processes to induce a construct definition of hope'. The data-based example is from a study of 25 adolescents (both well and hospitalized adolescents) who participated in defining ‘hope’. Results include a definition of hope consisting of four categories which seem to form a continuum of degree. The induced definition is used to demonstrate rules which have been put forth in the social science literature to guide the formulation of construct definitions. The relationship between processes of conceptualization and measurement is further demonstrated by examples of scale items to index hopefulness in adolescents. The scale items reflect the four categories of the induced definition of hope and comprise the inductively developed ‘Hopefulness Scale for Adolescents’.