This study aims to explore how collaborative teacher interaction is contingent upon teachers' immediate classroom and school-organizational contexts as well as broader societal and policy environments. Notwithstanding the widely acknowledged connection between teacher collegiality in schools and its beneficial effects, little systematic effort has been made to understand what types of teachers, under what contextual conditions, build and/or sustain collegial relationships with other teachers. In order to understand better a range of multilevel contextual factors associated with collaborative teacher interaction, this study intends to both elaborate and test an uncertainty management perspective as a theoretical framework. In addition, four conventional perspectives--a school climate perspective, a principal instructional leadership perspective, a curriculum policy perspective, and a national culture perspective--are also considered to see if a set of primary hypotheses derived from the uncertainty management perspective is empirically supported even after a range of other plausible hypotheses are simultaneously taken into account. Overall, the main findings from this study support an uncertainty management perspective which understands collegiality as a byproduct of the collective sensemaking of uncertainties, which reduces organizational members' feelings of discomfort with given uncertainties and thus helps them manage those uncertainties without actually removing them completely from given situations. Extensive international and U.S. data analyzed in this study substantiate the central proposition of the uncertainty management perspective that teacher collegiality has to do with teachers' collective effort to deal with various instructional and classroom-contextual uncertainties that they confront in their teaching. This result sheds light on the possibility that lateral collegial relationships among teachers may serve as a source of information processing, sensemaking, and problem-solving, whereby teachers can better manage to go through given situations of uncertainty. This study provides useful implications for educational policy and administration. In particular, given the fact that it is not always either possible or desirable to eliminate the sources of uncertainty in teaching, finding ways to help teachers manage the uncertainty through collaborative interaction with their colleagues is an important task for educational administrators and policy makers. Further, considering the wide variety of possible situations in which teachers confront instructional and classroom-contextual uncertainties, it is important for principals to explore various ways to actively share leadership roles and responsibilities with many teachers, so that individual teachers can become empowered agents to foster and sustain a collegial work environment. [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/en-US/products/dissertations/individuals.shtml.]