Everything around us that is not a simple untouched piece of nature has been designed by someone. Human society has found a great refuge in these designed objects or the artefacts, and thus has adapted vociferously to their inclusion into everyday life. From the early conception as art and then lately as scientific activity, now during the last few decades, designing has been understood as a fundamental aspect of human life. This understanding has become a motivating force in the last four decades for design research community. Remarkable theories, methods, models and approaches for designing have been propounded during this period by various active design researchers. Yet a comprehensive design theory remains largely an elusive dream, and usage of proposed methods in practice unimpressive. The dominant paradigms in design theory, though rich in description seem to lack interconnection. The thesis explores and questions the very foundations on which design theories have been built. Theoretical contemplation over designing is sought through asking why question, which brings in context to the forefront. Thus understanding context in designing is the central theme to this dissertation. Incidentally it is the context that holds key to the enhanced usage of design methods in practice. The thesis presents a basis to thaw the development of design theory, and provides a pragmatic approach to augment usage of design methods in practice. These objectives have been achieved through the approach outlined below. • An extensive discussion on the notion of context is presented, underpinned by the detailed survey of definitions and world views held in by various domains of studies in regard to context. The salient characteristics of context identified through this discussion have been used to articulate a concise definition of context. • A comprehensive dialogue, supplemented by the literature in design, incorporating dyv of design, designing, artifacts, and context has been put forth. The theoretical insight obtained has been abstracted into an elemental model of context in designing, that is then elaborated at length. • Definitions of context in designing, context of designing, and that of designing in context have been formulated, using the definition of context and the elemental model of context in designing. • The empirical validation of the proposed model of context in designing has been carried out, which runs across six design projects, accounts for academic; controlled; and industrial environment, as well as focuses on both individual and team designing. Four methods for data collection and analysis - Questionnaire survey, design protocol analysis study, replication protocol analysis, and participant observation study were employed in this exercise. • A detailed prescriptive study for development of aid to designers; in selection process of design methods has been carried out. Based on the issues identified in the literature and survey with designers, a measure to assess contextual usability of design methods (MACUM) was formulated. A web-based software tool based on MACUM has been developed for supporting design method selection process. The thesis concludes that the dominating paradigms in design theory only represent the partial perspective of designing. It is argued that, the proposed model of context in designing provides a sound basis to coherently redress the disjunctions between paradigms of design and progress towards a holistic design theory. And further on the practical end, the thesis underlines the contribution of MACUM towards sustained usage of design methods in practice.