THERE IS a shortage of science teachers in the U.S. (1) That is a problem because this country's future could depend on our expertise in science and technology. Fortunately, while there is no magic wand to increase the number of qualified science teachers, there is a way to extend the instructional impact of the teachers we have. And the advantage of this method is that it uses a technology that is popular among students and allows teachers to differentiate their instruction for stuents with diverse needs. Widely available software now makes it easy for teachers to establish class blogs. A blog is a website that contains text, audio, and video postings on a particular subject. In addition, the popularity of such software as iTunes now makes it possible for students to access high-quality instruction from class blogs long after they leave their science classes. While all students may not have Internet connections at home, students can access and download blog files at the community library or in school computer labs or media centers during study periods, after school, and during tutorials. SCIENCE INSTRUCTION IN DIFFERENTIATED CLASSROOMS When thinking about the potential of blogs to increase effective instructional time, it's worthwhile to first consider how science teachers provide high-quality, differentiated science instruction for all students in the classroom. For example, consider Ms. Daniels, a (composite) seventh-grade life science teacher, and three of her students. Ms. Daniels has a master's degree in science education and has been teaching life science for eight years. She stays current in her field and has participated in teacher development projects through the National Science Foundation. Over the past three years she has worked to differentiate instruction for the diverse students she teaches. Ms. Daniels teaches English-language learners (ELL students), students with individualized education programs, and gifted and talented students in her heterogeneous, mainstream science classes of 20 to 24 students. She differentiates instruction to help all students learn high-level science content and develop the academic language skills necessary to effectively communicate science concepts. She builds units and lessons around the enduring (2) that she and her colleagues have established for seventh-grade life science. She explains, Helping students focus on the essential questions provides context for learning and keeps students focused. It also allows students to demonstrate their level of understanding in various ways. Today, Ms. Daniels is teaching about mollusks. Ana, an ELL student who has been in the U.S. for three years; Robert, who reads at a fifth-grade level; and Taylor, who has been identified as gifted and talented, listen as Ms. Daniels describes the characteristics of mollusks and uses PowerPoint slides to display detailed photos of clams and other bivalves. Ms. Daniels speaks clearly as she points to illustrations and related vocabulary. The students take notes in their daily science journals. Every other week, Ms. Daniels holds individual journal conferences that engage students in academic discussions about their work. She wants students to understand that scientists do not work alone. Students learn to discuss concepts using scientific terms and expressions. In these conferences, Ana uses journal notes to practice the language of science. The conferences allow Robert to verbally express understandings he cannot make clear in writing. And they give Taylor the chance to discuss the links on the class blog that allow her to access more advanced content. At the beginning of each school year, Ms. Daniels conducts several lessons focusing on text structure. She uses overheads of pages from the science text to demonstrate to the students where and how they can find key concepts, new vocabulary, and important explanations. …