This action research study was conducted in an elementary school with a team of seven fourth- grade teachers. Transcripts of the fourth-grade teachers' discussions during their common planning sessions were recorded and analyzed. The data revealed that during collaborative planning sessions the teachers repeatedly referred to authentic assessments and their use in literacy instructional planning. The teachers interviewed each other on the use of authentic assessments in literacy. The interviews showed that the teachers found many benefits for instructional planning when using authentic assessments. They also had significant concerns about the time management needed in order to carry out an assessment-driven balanced literacy program. The analysis of the data indicates that teachers use authentic assessments to plan instruction in a collaborative manner as follows: *With the use of authentic assessments such as individual student conferences, running records, and student work, the teachers identified specific strategies, skills, and goals centered on their students' strengths and needs. Their instructional planning for the differentiation in instruction emphasized the success of all students. *Conversations with colleagues allowed the teachers to gain new ideas and insights as they shared strategies for instruction and information about materials and unit plans.*The teachers highly valued listening to students' conversations and problem-solving strategies. *The teachers were able to provide helpful feedback to their students. *The cycle of teaching, learning, and assessing is rooted in the specific experiences, ideas, strengths, and needs of each student. *The implementation of the teaching, learning, and assessing cycle requires professional development and time for reflection and planning. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]