Teachers play a critical role in leading effective laboratory experiences. By carefully introducing the experiences in ways that are aligned with the learning goals of the science course and leading discussions and answering questions, the teacher can support students in linking their laboratory experiences to underlying science concepts. By selecting laboratory experiences that are clearly related to the ongoing flow of classroom science instruction, the teacher can integrate student learning of both the processes of science and important science content. Yet the undergraduate education of future high school science teachers does not currently prepare them with the pedagogical and science content knowledge required to carry out such teaching strategies. Undergraduate science departments rarely provide future science teachers with laboratory experiences that follow the design principles derived from recent research—integrated into the flow of instruction, focused on clear learning goals, aimed at the learning of science content and science process, with ongoing opportunities for reflection and discussion.

Once on the job, science teachers have few opportunities to improve their laboratory teaching. Professional development opportunities for science teachers are limited in quality, availability, and scope and place little emphasis on laboratory instruction. In addition, few high school teachers have access to curricula that integrate laboratory experiences into the stream of instruction, although such curricula might help them in improving the instructional quality of laboratory experiences. Few high schools support science teachers in improving their laboratory teaching by providing appropriate, ongoing professional development, well-designed science curricula, and adequate laboratory facilities and supplies.

The capacity of teachers and schools to advance the learning goals of laboratory experiences is affected by laboratory facilities and supplies and the organization of schools.

Direct observation and manipulation of many aspects of the material world require adequate laboratory facilities, including space for teacher demonstrations, student laboratory activities, student discussion, and safe stor-