The literature on self and identity is vast but chaotic. A kaleidoscopic set of conceptualisations, some of which have been outlined in Chapter 1, is in disarray. Methods of assessment of parameters of identity, deriving from disparate conceptualisations of self and identity, are often unrelated. They might, for example, refer to self-labelling, use repertory grid technique, assess social roles, or estimate social identification, but without any consistently conceptualised interrelationship between them. Other studies may concern self-esteem, or notions of identity achievement or failure, or, most common of all, appeal to various ad hoc measures associated with specific parameters such as self-efficacy, introversion, or locus of control. Each tradition proceeds within its own terms with seemingly little awareness of others, giving rise to a plethora of results, the consequences of which are partial findings that cannot readily be related to one another. Further, while experimental approaches can provide powerful means for explicating certain phenomena, for example, the impact of social categorisation on group processes, they cannot substitute for direct assessments of parameters of identity associated with spontaneous expressions of identity in directly experienced everyday social milieus.