This study explores how rationales for information technology use relate to the extent of its assimilation in organizations and considers whether and how rationales associated with the technology-in-practice are transformed as the organization makes use of the technology. A multiple-case study of electronic data interchange (EDI) adoption and assimilation was analyzed, looking at both institutional and strategic rationales for EDI use. The degree of assimilation was greatest among those organizations that cited a strategically-oriented rationale for using EDI. The study also found evidence of a shift from institutional to strategic rationales in several organizations as they decided to extend their use of EDI beyond their initial implementation. Shifts in rationale emerged as organizational members gained greater exposure to the organizing vision of the larger EDI community and, to a lesser extent, as they experienced improvements in organizational performance through the use of EDI.