The term "imaginary audience" was introduced by David Elkind to refer to the tendency of adolescents to falsely assume that their appearance or behavior is the focus of other people's attention. Having an imaginary audience is believed to result in the self-consciousness that is characteristic of adolescence and is often linked conceptually with personal fable, which involves having a strong belief in one's own uniqueness. Researchers have assessed imaginary audience by asking adolescents questions about what they would do in social situations that are potentially embarrassing (e.g., you arrive at what you thought was a costume party but you are the only person in a costume). More recently, Daniel Lapsley and his colleagues described imaginary audience as reflecting the developmental process of separation-individuation and measured it by assessing the frequency of adolescents' daydreams about themselves and others.
Elkind, David. "Egocentrism in Adolescence."Child Development 38(1967):1025-1034.
Elkind, David, and Robert Bowen. "Imaginary Audience Behavior in Children and Adolescents." Developmental Psychology 15, no. 1 (1979):38-44.
Lapsley, Daniel K., David P. Fitzgerald, Kenneth G. Rice, and Sara Jackson. "Separation-Individuation and the 'New Look' at the Imaginary Audience and Personal Fable: A Test of an Integrative Model." Journal of Adolescent Research 4, no. 4 (1989):483-505.
Vartanian, Lesa Rae. "Separation-Individuation, Social Support, and Adolescent Egocentrism: An Exploratory Study." Journal of Early Adolescence 17 (1997):245-270.