This dissertation focuses on strategy formation of firms as it unfolds over time and in context. The research questions are defined to take into account the complexity of this phenomenon, in that the themes emanating address the involved structures, processes and managerial agency as the roles and influences of managers.A "semi-deductive" methodology is introduced in order to make use of the richness of theories that pertain to the research questions. The logic behind this conduct is to first construct an interdisciplinary interpretation system based on a thematic bridging of theoretical texts. In a second stage of creating knowledge, the themes are not only retained but also extended by virtue of empirical texts. A case study covers both the organizational and sectorial level of analysis during a period of six years; thus including all the competing firms within an industry, as well as the broader context in which these companies operated. The individual level is represented by the top management groups of all firms. On both theoretical and empirical grounds, a socio-cognitive perspective emerges in which an emphasis is placed on the reciprocity between individuals as acting subjects and their social contexts. The interaction is seen as the linkage that binds actors, structures and processes. Strategy formation of the firm is uncovered as a process of structuration encapsulating distinguishable structures, interaction processes and actors. The managerial role of coupling interactions is featured. The influence of managers is discussed in terms of a freedom of interpretation and a freedom of physical action. This study carries empirical as well as theoretical implications for several research fields such as industrial evolution, the management of strategic change and the theory of the firm in general. Here, the socio-cognitive framework generated may serve as a basis for uniting individual and social aspects. The "semi-deductive" methodology may also find a broad field of application. / <p>Diss. Stockholm : Handelshögskolan, 1993</p>