Information System Development (ISD) is a knowledge-intensive activity demanding coordinated application of business and Information Technology (IT) professionals’ expertise. However, knowledge transfer between these groups is challenging, requiring the bridging of their different thought worlds. The problem is even more pronounced for project teams involving external IT consultants with whom the business professionals had no prior collaboration history. Therefore, a relevant but understudied issue is the motivations of business and external IT professionals in knowledge transfer. This paper applies the theory of social interdependence, which explains group cooperation, to study the problem. Based on the theory, a model is developed which proposes that goal, task, and reward interdependencies affect the extent of knowledge transfer between these groups during an ISD project. Construct operationalization and plan for data collection are discussed.