Purpose. The purpose of this study was to determine if there is a difference in the degree of teamness in middle school teams whose schools have strong evidence of the five dimensions of a Professional Learning Community, compared to middle school teams in schools that do not have strong evidence of the five dimensions of a Professional Learning Community.

Methodology. The researcher employed a descriptive and ex post facto study, which included middle school principals and their respective teachers in the County of San Bernardino, California. The two survey instruments utilized for data collection consisted of Huffman and Hipp's (2002) "Professional Learning Community Questionnaire" and Harvey and Drolet's (2003) "Characteristics of Effective Teams Survey."

Findings. This study found that the aggregate of teacher responses rendered a significant difference in the each of Harvey and Drolet's 17 Characteristics of Effective Teams. Additionally, this study found that the means of the school means displayed a significant difference in 15 of the 17 Characteristics of Effective Teams. The data also revealed that both the schools with strong evidence of a Professional Learning Community and those schools without strong evidence of a Professional Learning Community had a substantial degree of teamness.

Conclusions. Although each group had considerable degrees of teamness, the significant differences in means put forth the conclusion that schools attempting to build a Professional Learning Community should attend to each of the 17 Characteristics of Effective Teams. It was also concluded that schools without strong evidence of a Professional Learning Community ought to spend additional time on teambuilding activities that nurture collegial relationships.

Implications for Action. Recommendations were made to assist practitioners in the charge of building a Professional Learning Community. Specific teambuilding processes were suggested. Furthermore, the researcher proposed that school principals should designate time to properly train, develop, and empower individuals who will be leading teams.