Although there are positive aspects to this type of reading instruction, there are also two main challenges that exist at every grade level. According to Irene Fountas and Gay Su Pinnell, "some students will work on very basic reading skills such as word analysis and comprehending simple texts" while other students may be working on more advanced reading skills and strategies with increasingly challenging texts. In addition, "all students need instructional support so they can expand their competence across a greater variety of increasingly challenging texts." (Fountas and Pinnell). Thus, it takes a lot of strong planning and organization from the part of the teacher in order to successfully implement Guided Reading so that it meets the needs of all learners. Simultaneously, “a teacher’s goal is to strive to provide the most effective instruction possible and to match the difficulty of the material with the student’s current abilities. Materials should provide a challenge that is “just right” for the students” (Iaquinta, 2006). Guided Reading is a complex approach and teachers are essential in the development and execution of a Balanced Literacy program.