Since 1996 ABET has mandated that undergraduate engineering degree granting institutions focus on learning outcomes such as professional skills (i.e. solving unstructured problems and working in teams). As a result, engineering curricula were restructured to include team based learning--including team charters. Team charters were diffused into engineering education as one of many instructional activities to meet the ABET accreditation mandates. However, the implementation and execution of team charters into engineering team based classes has been inconsistent and accepted without empirical evidence of the consequences. The purpose of the current study was to investigate team effectiveness, operationalized as team viability, as an outcome of team charter implementation in an undergraduate engineering team based design course. Two research questions were the focus of the study: a) What is the relationship between team charter "quality" and "viability" in engineering student teams, and b) What is the relationship among team charter "quality," teamwork mental model "similarity," and "viability" in engineering student teams? Thirty-eight intact teams, 23 treatment and 15 comparison, participated in the investigation. Treatment teams attended a team charter lecture, and completed a team charter homework assignment. Each team charter was assessed and assigned a quality score. Comparison teams did not join the lecture, and were not asked to create a team charter. All teams completed each data collection phase: a) similarity rating pretest; b) similarity posttest; and c) team viability survey. Findings indicate that team viability was higher in teams that attended the lecture and completed the charter assignment. Teams with higher quality team charter scores reported higher levels of team viability than teams with lower quality charter scores. Lastly, no evidence was found to support teamwork mental model "similarity" as a partial mediator of the team charter "quality" on team "viability" relationship. Foci for future research opportunities include using: a) online data collection methods to improve participant adherence to similarity rating instructions; b) story or narratives during pre- and posttest similarity rating data collection to create common levels of contextual perception; and c) support to ensure charters are integrated into the full project life cycle, not just a pre-project one time isolated activity. Twenty five sections, on average, of EDSGN 100 are taught each spring and fall semester. Consistent instructor expectations are set for the technical aspects of the course. However, ideas to foster team effectiveness are often left to the discretion of the individual instructor. Implementing empirically tested team effectiveness instructional activities would bring consistency to EDGSN 100 curriculum. Other instructional activities that would be of benefit to engineering educators include qualitative inquiry--asking intrateam process questions (at the mid-point of the project) and in-class reflection--dedicated time, post project, to discuss what went well/not well within the team. [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.]