In the physical spaces of writing classrooms and the conceptual spaces of writing practice and pedagogy, knowledge about computers is constructed by many individuals, groups, and institutions. Each has a stake in defining what computers mean for education and the role computers should play in the everyday life schools. Some of these stakeholders are immediate members of our school communities, such as students, teachers, administrators, and technology support staff. Some are not, such as politicians, researchers, and computer manufacturers. The effect of these often competing stakeholders is one of contested space. Writing teachers encounter contested space when we decide to make computers a considered part of our teaching. Contested space too often creates a lack of technical and pedagogical resources for computers and writing instruction. The most successful writing teachers are able to improvise and collaborate in order to create or gain access to these resources. This dissertation draws on Edward Soja's Thirdspace theory and case studies of three successful computers and writing teachers to describe contested space, its effects on writing instruction, and approaches to professional development. Soja's theory helps us identify how the physical Firstspaces and conceptual Secondspaces of computers in our schools are shaped by powerful stakeholders. Thirdspace, the third spatiality of Soja's trialectics, describes the improvisational experience of computers and writing instruction. It also suggests a set of core beliefs that we can use to help plan and facilitate professional development activities that support the multiliteracies and sense of agency teachers need to transform the contested spaces of computers and writing in their classrooms and schools. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]