The purpose of this study was to explore and reveal the process behind how teachers that administer standards-based tests implement instructional practices in the classroom according to the accountability measures of NCLB. The study revealed how teachers in two different school settings prepared their students for the yearly standardized test. In addition, perspectives from administrators and teachers in a Montessori public school and a traditional school setting was included to explain how teacher attitudes toward NCLB are involved in the test preparation process and how specific instructional practices affect student achievement. This research study was conducted using qualitative and quantitative research methods which discovered many similarities and differences between the two teaching and learning environments. The goals of the study were to determine (a) whether there was a significant difference between the Montessori public school teachers and the traditional public school teachers in terms of their perceptions of daily instructional practices, and (b) the significant difference between the Montessori school teachers and the traditional public school teachers in terms of their perceptions toward standardized tests as required by the NCLB law. The primary methods used in the study included a survey and face-to-face interviews with administrators and teachers' in Grades 3-8. Findings from the study showed that both groups of teachers implemented many of the same instructional practices, but in different ways and from different perspectives as shared by the voices of the teachers throughout the study. Teachers made it a goal to prepare students for standardized testing according to the state requirements. In both learning environments students exhibited success on standardized test. At the administrative level the findings lead to the conclusion that the administrators at both sites support the review and use of data from school-wide assessments and state exams to help their students achieve on standardized testing and their teachers are fully supported by the administration during testing. However, it was evident that the way in which the two schools approached testing was different. [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.]