US High School Science Lab Experiences Often Poor, But Research Points Way To Improvements

The committee that wrotethe report conducted a comprehensive review of research on how U.S.high school science labs affect science learning, and on the whole,available knowledge is inadequate, it said. Research gaps, including alack of consensus on how to define these labs or their purpose, make itdifficult to reach conclusions on the best approaches to laboratoryteaching and learning. However, sufficient evidence shows that thenation's high school science labs generally do not follow fourestablished principles for effective science instruction:

+ Design science lab experiences with clear learning outcomes in mind
+ Thoughtfully sequence lab experiences into science instruction
+ Integrate learning science content and learning about the processes of science
+ Incorporate ongoing student reflection and discussion

"Althoughmore rigorous research on the role and value of high school sciencelaboratory experiences is needed, existing research is useful forcurriculum designers, teachers, and other education leaders to makeimprovements now in how science teaching and lab experiences arestructured to support learning," said committee chair Susan Singer,professor of biology, Carleton College, Northfield, Minn. "New researchefforts should include the systematic collection and dissemination ofthe best classroom practices."

On average, U.S. high schoolstudents enrolled in science classes spend about one period each weekon lab work, such as comparing different cell types under a microscopeor adding a solution of known acidity to a solution of unknownalkalinity. A "laboratory" may refer to a room where students usespecial equipment to carry out well-defined procedures, or solely todifferent types of science activities. The committee used the term"laboratory experiences" to describe those that take place in anyrelevant setting and that provide students with opportunities tointeract directly with the material world or with data drawn from it --using the tools, data-collection techniques, models, and theories ofscience.

Students should participate in a range of lab activitiesto verify known scientific concepts, pose research questions, conceivetheir own investigations, and create models of natural phenomena, thereport says. This kind of broad exposure could enhance theirunderstanding of the relationships between empirical research andscientific theories and concepts.

Historically, lab experienceshave been disconnected from the flow of science lessons in U.S.classrooms, and this remains typical, the report says. Such labexperiences help develop some aspects of scientific reasoning and playa role in boosting students' interest in science, but they have littleeffect on helping them master subjects. These exercises are oftennarrow in scope and more focused on mechanical procedures than onmeaning.

In recent years, researchers have begun to design andstudy "integrated instructional units" that connect the lab with othertypes of science learning. In this approach, students help frameresearch questions, design and execute experiments, and constructscientific arguments and explanations -- key elements of the scientificprocess. Few large-scale studies have been conducted on these units,the report says, but limited evidence shows promising gains for diversegroups of students in understanding the subject matter, developingscientific reasoning skills, and boosting interest in science. Oneexample engages students in performing a series of chemical reactionsand weaves those lessons with other forms of chemistry instruction.Preliminary results from an ongoing five-year study in the MontgomeryCounty, Md., school district were so positive that this instructionalunit was scaled up from five middle schools to more than 30.

Severalfactors play a role in the prevalence of typical, old-style lab work,the report says. Teachers are rarely trained to effectively lead labexperiences that follow the four design principles. The way schedules,space, and other resources are organized in most high schools also mayimpede teachers' and administrators' learning about how to carry outeffective science instruction. Moreover, if state science standards areinterpreted as encouraging the teaching of certain science topics atvarious grade levels, teachers may feel too pressed for time to teachlabs well.

In an increasingly complex, high-tech society, U.S.high school graduates need a basic understanding of science andtechnology to lead productive lives, the report says. To improve theirunderstanding, most science laboratory experiences must be reformed.

Thestudy was sponsored by the National Science Foundation. The NationalResearch Council is the principal operating arm of the National Academyof Sciences and the National Academy of Engineering. It is a private,nonprofit institution that provides science and technology advice undera congressional charter. A committee roster follows.