The purpose of this study is to determine the levels of concern of Illinois principals regarding the adoption of an evaluation system modeled after Charlotte Danielson's Framework for Teaching. Principal demographics and involvement in the use of and professional development surrounding Charlotte Danielson's Framework for Teaching were studied for their impact on the concerns of principals. Finally, the concerns of principals were determined using both the Stages of Concern Questionnaire and the Open-Ended Statements of Concern. The study used a quantitative research design to identify the levels of concern of principals in the adoption of a new innovation, Charlotte Danielson's Framework for Teaching as the basis for evaluating teaching practice. Descriptive and inferential statistics were used to provide insight into principals' concerns implementing Danielson's Framework. The target population was the 2960 K-12 public school principals in Illinois, excluding principals working for Chicago Public Schools. The online survey was completed by 313 principals. The results of the study found that the implementation of Danielson's Framework for Teaching has raised concerns for principals including the amount of time, paperwork, and inability to perform other duties. In addition, gender and the average number of teacher evaluations per year influenced the concerns of principals. Finally, the variables studied included: years of experience using Danielson's Framework for Teaching, principal self-rating of knowledge of Danielson's Framework for Teaching, and the number of professional development activities also impacted principals' concerns. Based on the results and the current literature, recommendations for educational practitioners and for future research were made. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]