Embedded in FOSS is some of the best research information on how people learn. The sequencing of investigations reflects the findings that conceptual knowledge is progressive and cumulative over time. No one ever learns the laws of physics, the workings of biology, or the grand ideas of chemistry in one course. Advanced concepts are learned through years of experience by building upon prior knowledge. Similarly, the ordering of experiences within FOSS investigations reflects the findings that knowledge is retained better through the exploration of concepts from various perspectives, taking more time to study, reflect, and discuss what is being learned. These applications of research have been verified through extensive testing of FOSS in many classrooms. And through these applications of research in FOSS, many educators have expressed that they have become more expert at what they understand and do in classrooms.

The proof that FOSS works can be seen in students' behaviors, teachers' comments, and some regularly reported student gains. FOSS has received hundreds of anecdotal success stories. Most praise the high quality of what is learned and the positive attitudes students develop toward science. Many success stories are from teachers who have rediscovered the joys of teaching through the FOSS pedagogy. Some are from studentsboys and girlswho comment on their favorite FOSS experiences or send pictures and journal notes about what they have studied. Large urban school districts such as Los Angeles and Fresno have collected test data that indicate test scores have improved significantly since the implementation of FOSS.

We are pleased with the reputation the FOSS program has earned. In the words of one teacher, "FOSS brought joy back to teaching and quality science learning back into the classroom." Because so much of the FOSS success is founded on applications of research and the field-testing of the product, one might question the rationale for revising the curriculum. Why make adjustments to something that's already working so effectively? Or, to rephrase the old adage, "If it ain't broke, why fix it?" It's a very reasonable question, and it has several answers.

The first is that the times have changed. In the past nine years since FOSS entered the marketplace, technology has become more prevalent in schools. Ways to assess thinking have improved. Knowledge about learning has increased.

The second reason is that FOSS developers are continual learners, and every year new research information, especially from the fields of cognitive science, brain physiology, and developmental psychology suggests ways to improve curricula and teaching. And information from users of the program suggests ways to improve.

Without affecting the integrity of the original program, the thorough re-working of FOSS allowed us to embed new knowledge and experiences. As good as the original program was, it's now even bettermore precise, more clearly expressed, more broadly based, and (most important of all) more flexible and useful.

1. FOSS was in schools before the National Science Education Standards were developed and published. It is not surprising that FOSS matched the standards very well, especially in the areas of content knowledge and inquiry. But a few "new" standards concerning careers and the history of science appear in the NSES. FOSS has been revised to meet most of the NSES that it did not include in its original version.



2. In the original FOSS, assessments were put into a separate folio and placed at the end of a module. It was expected that teachers would draw from the set of hands-on, pictorial, and narrative assessments to determine student progress. We found, however, that teachers tend to not use the assessments until the end of the instruction, so the assessments were being used as summative exams. Because the FOSS assessments are designed to inform teachers of student progress (not as final tests), the assessments are now embedded within the investigations so that teachers will know if more time and experience are needed for students to understand what is being taught. And they will learn which students need special assistance. The revised assessments are both formative and summative. They are accompanied by more detailed scoring guides, student examples, and suggestions for what to do with the results. Although all assessments are designed to inform teachers so that they will know what to do next, FOSS also suggests ideas to consider if grades are to be reported.

3. The questioning strategies in the original FOSS gave powerful suggestions for engaging students in thinking about aspects of each investigation. Some questions were narrow and integrating; some were broad and open-ended. Many teachers have become quite expert in using the FOSS questioning strategies and have found them useful across all areas of instruction. In the revised curriculum, the questioning strategies are woven into the teacher guide, and teachers are encouraged to engage students in thoughtful discourse. Discourse is a term we use to describe student-student and teacher-student verbal interactions that are so important to under-standing. Research suggests that such discourse, when guided by appropriate questions, helps learners connect ideas with prior experiences and relates ideas that might have been experienced separately. Connected ideas are remembered better than unconnected ideas.



4. FOSS has always involved students in reading and other language arts experiences related to the science investigations. The curriculum encourages going beyond hands-on experiences to include simulations and reading resources. In the original curriculum, trade books and library references were listed or made available to extend student understanding toward abstractions. Research shows that understanding what one reads is improved if preceded by appropriate experiences. Bringing some knowledge to reading increases one's understanding of the reading. After much investigation into reading materials, FOSS staff came to the conclusion that quality books that contain appropriate and accurate content, developmentally appropriate content, and appropriate reading levels were few and far between, and those that were well done usually went out of print before we could prepare a list of them. Thus a set of readers called Science Stories was developed. Unlike other reading materials, these are written to build upon and extend classroom experiences. In use, they are a seamless part of the science instruction. The Science Stories were written to integrate: a range of types of writing expository, narrative, and technical; a range of types of literature, fictitious stories, newspaper articles, step-by-step directions, and encyclopedic references; and a range of writing genres, histories, biographies, poetry, and folk tales. Very rich language arts experiences not available elsewhere are deeply woven into the fabric of the curriculum.



5. When FOSS was first written, computers were not common in elementary schools and websites were practically unknown. FOSS now provides, for grades 3-6, a website (www.fossweb.com) that allows students and teachers to communicate from school to school, share data on common projects, exchange ideas, and take students beyond the walls of the classroom. For schools without connections to the Internet, an interactive CD-ROM version that includes simulations will be available. As with the Science Stories, the CD can be used closely with the hands-on investigations.

6. There are many other features that improve FOSS—some additional activities, some improved equipment, new teacher preparation videos with more classroom examples, more back-ground on science for teachers, more information on student misconceptions, vignettes of classroom interactions, take-home extensions, math-related problems, and more. As American companies move into the next millennium and are challenged by ever fiercer global competition, schools need to graduate well-prepared students from high schools and colleges for a world that is becoming more scientific and technology oriented. Elementary experiences set the foundation for later learning, thus the time is now for a "re-engineered" version of the FOSS curriculum classic. We offer it with confidence and enthusiasm to new generations of teachers and students and also, with thanks, to the people in the FOSS family the thoughtful professionals and colleagues we are proud to call our friends who have used and helped make FOSS a successful curriculum.