Organizations world-wide are pushed to restructure work around teams by a variety of global forces to enable more rapid, flexible, and adaptive responses to the unexpected (Drucker, 2003;Glassop, 2002;Kozlowski & Ilgen, 2006) and to provide more innovative and comprehensive solutions to complex organizational problems (cf. Beers, 2005). As a result of this shift in the structure of work, team effectiveness has become a salient organizational concern. Individual skills are necessary but insufficient for good team performance (Salas, Dickinson, Converse, & Tannenbaum, 3 1992). Empirical research, however, demonstrates considerable variance in team effectiveness (e.g., Hackman, 1987).Team members need to have both accurate and detailed understandings of the requirements of team functioning. In other words, they need to build up shared mental models (Cannon-Bowers, Salas, & Converse, 1990), which will help them predict, adapt, and coordinate with one another, even under stressful or novel conditions. To create shared mental models, team members need to challenge each other's ideas and assumptions constructively (Senge, 1990). The latter behavior is part of the team learning behaviors defined by Edmondson (1999).The teams we address in this study are project teams in knowledge intensive organizations (cf. Starbuck, 1992). Many knowledge-intensive work settings are characterized by overload, ambiguity, and politics. Highly specialized professionals, often drawn from different functional disciplines or departments are brought together to contribute their expertise to a unique achievement, for instance, establishing an oil refinery in a place where land is to be claimed from the sea. The project teams face a multitude of problems and possible solutions. There is no one best way of knowing which problems and solutions to select; therefore, multiple stakeholders need to interact with one another continually (Alvesson, 2004). The most important performance outcome for these teams is the quality of the product they deliver to their clients.Teamwork in these project teams consists primarily of gathering information, know-how, and feedback through interpersonal exchanges within the team and across its borders, resulting in new knowledge presented to colleagues and/or clients (cf. Starbuck, 1992;Turner, 1999). The value of the team approach lies, among others, in the cross-functionality of its members, who provide the opportunity for timely 4 integration of critical information not only from their functional background but also from various external personal networks. To translate the diversity of viewpoints into project success, team members must adopt an inquiry orientation in which they mutually explain their positions (Edmondson & Smith, 2006). Hence they gain better understanding of the whole project by viewing it through alternate eyes (Brown & Eisenhardt, 1995). The importance of interpersonal exchanges in these project teams points to the value of team learning behaviors aimed at gaining understanding ...