Building Background Knowledge.

[ILLUSTRATION OMITTED] Too often, students enter our classrooms with insufficient knowledge of physical science. As a result, they have a difficult time understanding content in texts, lectures, and laboratory activities. This lack of background knowledge can have an impact on their ability to ask questions and wonder--both key components of inquiry. The solution, in many schools, is comprehension strategy instruction, in which students are taught how to use cognitive processes to understand texts. Literacy experts often recommend that science teachers focus on comprehension tools, such as visualizing, predicting, summarizing, questioning, making connections, and inferring. We argue, however, that without sufficient background knowledge, none of these tools will be effective. In this article, we demonstrate the impact that building background knowledge through wide reading can have on student achievement. With this method, students read a selection of texts on a given subject. We identify a number of reasons why wide reading is not commonly used in the classroom and how to address those concerns. Developing background: Direct and indirect experiences Students can develop background knowledge through both direct and indirect experiences (Marzano 2004). Direct experiences include activities such as field trips and labs. These are powerful ways to enhance student understanding. Consider, for example, the impact of visiting a space museum or a science center. We recently had the opportunity to take our ninth-grade students to see a museum exhibit focused on water. The experience provided a foundation for understanding this natural resource and its importance in climate change. By the end of the day, our students had come to understand the formula at the center of the exhibit: using water = using energy = carbon dioxide (C[O.sub.2]) emissions = climate change. Direct experience with the exhibit brought this idea home for our students. However, field trips and labs are time-consuming and costly. Although they are excellent ways to build background knowledge, they are also not available for every lesson we teach, and they often do not provide the specifics students must know and understand to be successful in the physical sciences. So instead, we rely on indirect experiences to build students' background knowledge. Wide reading--in which students independently read books, magazines, or other available materials for an extended period of time--can be an effective indirect way to build background knowledge. Unlike free, voluntary reading, this method is focused on a specific topic, such as wave motion or the rock cycle. Students read materials at their own reading level--an important and often overlooked aspect of independent reading. To be effective, students must understand what they are reading so they can connect new vocabulary and ideas. Finally, they need time every day to develop a habit of reading for information in their science classes. This mirrors the lives of scientists, who read widely on nearly a daily basis, in journals, websites, field notes, and the like. Measuring student achievement While we know that building background knowledge is important for understanding content, we wanted to find out whether focusing on this aspect of teaching would improve student achievement. To test our hypothesis, we selected one section of ninth-grade Earth science students for an intervention unit on plate tectonics; students in other sections of the course served as the control group. We also tested one class of 11th-grade physics students. However, because of the small number of students enrolled in the class, we compared their scores on one intervention unit--on waves--with scores in other assessed areas on the comprehensive physics exam, instead of assigning a control group. During these units of investigation, students in the intervention classrooms read widely for 10-12 minutes of class time each day. …