Preparing Science Teachers
Much is expected of U.S. science teachers. Student achievement in science, engineering, and technology is directly linked in public discourse with the nation’s economic prospects. Moreover, the landscape of what science teachers might be expected to know and be able to do is very large. Depending on the grades they teach, science teachers may be expected to be knowledgeable about basic ideas and content from at least five academic disciplines: biology, chemistry, earth science, mathematics, and physics. They are expected to have a facility with different kinds of scientific inquiry and also, like any teacher, to possess pedagogical content knowledge—that is, to understand how students learn particular content and how to teach it.
Fortunately, there is a large body of scholarship on teaching and learning science, although it is largely descriptive and only a small portion of it is directly relevant to the committee’s charge, which was to consider the extent to which the coursework and experiences required of prospective science teachers are consistent with converging scientific evidence. As with the other two subjects, we first describe the research base and then present the evidence using four questions:
What do successful students know about science?
What instructional opportunities are necessary to support successful students?
What do successful teachers know about science and science teaching?
What instructional opportunities are necessary to prepare successful teachers?
THE RESEARCH BASE
Although there is a wealth of material on science learning and teaching, a recent committee that considered science learning and teaching described this work as mostly “short in duration and limited in scope, focusing on a few students or a few classrooms, [examining] some small part of the vast domain of science” (National Research Council, 2007, p. 212). The report adds that science learning is complex and that “the research on learning cannot be reduced to a few ‘what works’ bullets without losing much of its value” (p. 212). We are greatly indebted to the work of this and several past National Research Council (NRC) committees that have produced a number of reports that were extremely useful to us.
First, National Science Education Standards (National Research Council, 1996) provided a definitive resource for the question of what students need to learn about science. These standards were designed as a way to coordinate and update previous science standards that had been developed by the National Science Teachers Association (NSTA) and the American Association for the Advancement of Science (AAAS).
Another key resource for our committee was Taking Science to School (National Research Council, 2007). This report summarized the evidence and drew conclusions from the research on science learning and on how science should be taught in K-8 classrooms. The report drew on many sources of evidence about science and learning and built on findings from previous NRC reports on learning in young children as well as older children and adults, mathematics learning, and assessment. The report synthesizes disparate sources of insights related to science education, such as work that describes the building blocks of science learning in young children, and that maps the development of proficiency in different aspects of science.1
These and other reports, as well as meta-analyses conducted by Davis, Petish, and Smithey (2006) and by Shroeder and colleagues (2007), were particularly useful to us in meeting our charge of identifying consensus in the field and considering the extent to which teacher preparation programs in science reflect that consensus.2 In general, however, we note that the literature on science education includes more professional judgments and
reasoning about what students and teachers should know than empirical research. Interestingly, less empirical research is available in this field than in the other two we examined. In general, the field of science education is currently dominated by discussions and plausible recommendations regarding what students and teachers should know, but our confidence in those recommendations is tempered by the limited descriptive and experimental empirical evidence that supports them. This circumstance positions the field well for important research on teaching and teacher education in the future.
WHAT DO SUCCESSFUL STUDENTS KNOW ABOUT SCIENCE?
There is no research that directly addresses the question of what students should know. Instead, as in other fields, educators rely on the judgments of experts to determine what should be taught. Although the value of studying science for those who do not intend to pursue a career that requires scientific knowledge and skills is not widely appreciated, considerable attention has been paid to the question of what science proficiency for all students should mean. This attention is especially important in the context of evidence that U.S. students’ performance in science on international comparative studies has remained stagnant and is below that of many of the nation’s economic competitors.
The 2007 results of the Third Trends in International Mathematics and Science Study (TIMSS) show no improvement in the overall performance of U.S. 4th or 8th graders since the 1995 TIMSS. Looking only at the percentages of U.S. students who performed at or above the advanced level in science, performance has declined for both grades since 1995 (National Center for Education Statistics, 2007). Results from the Programme for International Student Assessment (PISA) for 2006 show that, overall, U.S. students performed below the average for the 57 participating countries, though the percentage of U.S. students performing at the highest level was comparable to that of countries with much higher overall scores. The PISA results indicated that socioeconomic differences accounted for much of the disparity in U.S. students’ science performance (Organisation for Economic Co-operation and Development, 2007). Thus, we look first at the arguments for viewing proficiency in science as important for all students. We then look at science standards more generally.
Science for All Students
Taking Science to School (National Research Council, 2007) addresses the question of what science all children should be expected to learn. The report, which focuses on K-8 science education, argues that educators un-
derestimate what young children are capable of as students of science and calls for extensive rethinking of how teachers are prepared. Taking Science to School argues that science is an essential component of K-8 education for several reasons:
Science is a significant part of human culture and represents one of the pinnacles of human thinking capacity.
It provides a laboratory of common experience for development of language, logic, and problem-solving skills in the classroom.
A democracy demands that its citizens make personal and community decisions about issues in which scientific information plays a fundamental role, and they hence need knowledge of science as well as an understanding of scientific methodology.
For some students, it will become a life-long vocation or avocation.
The nation is dependent on the technical and scientific abilities of its citizens for its economic competitiveness and national needs.
Thus, the report makes clear that science education is important for all students, regardless of their interests and aspirations, because it prepares them to understand and evaluate information and to use evidence when making decisions. AAAS makes a very similar argument in Science for All Americans (American Association for the Advancement of Science, 1991), a consensus-based report that reflects the judgments of a broad array of scientists and science educators. The report asserts that a “science-literate person is one who is aware that science, mathematics, and technology are interdependent human enterprises with strengths and limitations; understands key concepts and principles of science; is familiar with the natural world and recognizes both its diversity and unity; and uses scientific knowledge and scientific ways of thinking for individual and social purposes.”
In considering what students need to learn about science, Taking Science to School hoped to move beyond the dichotomy between content knowledge and skills, arguing that these two elements are completely intertwined in the study and practice of science. To develop science proficiency is to acquire a body of knowledge while also learning how knowledge is “extended, refined, and revised” (National Research Council, 2007, p. 26). The report stresses the value of science literacy even for those who do not ultimately enter a science-related career because students need to understand science as a process and to recognize the precise scientific meanings of words that have different meanings in everyday usage, such as theory, hypothesis, data, evidence, and argument (National Research Council, 2007).
The report identifies four strands of scientific proficiency as impor-
tant for all students, arguing that successful students (National Research Council, 2007, p. 2):
“Know, use, and interpret scientific explanations of the natural world”—they acquire facts and conceptual structures that incorporate those structures, and use them to understand many phenomena in the natural world.
“Generate and evaluate scientific evidence and explanation”—they have the knowledge and skills to build and refine models based on evidence, including designing and analyzing empirical investigations and using empirical evidence to construct and defend arguments.
“Understand the nature and development of scientific knowledge”—they recognize that science is a particular kind of knowledge with its own sources, justifications, and uncertainties; and that predictions or explanations can be revised on the basis of new evidence or a new conceptual model.
“Participate productively in scientific practices and discourse”—they understand the norms of the practice of science and how to participate in scientific debates or adopt a critical stance, and are willing to ask questions.
A National Academies report, Rising Above the Gathering Storm (National Academy of Sciences, National Academy of Engineering, and Institute of Medicine, 2007), also addressed the importance of science, technology, engineering, and mathematics (STEM) education in the United States, with a particular focus on high school preparation. The report grounds its argument in the need for skilled workers to fuel economic growth, asserting that the nation needs to prepare a large pool of students to enter STEM majors in college. The report concludes that all students should have access to a solid foundation of science coursework in high school. Without a doubt, the proposition that a strong science, or STEM, education is fundamental for all students has been widely embraced by policy makers, as a recent issue of Technology Counts demonstrates (Editorial Projects in Education, 2008).
The report describing the National Science Education Standards, was developed through a multiyear consensus process with input from scientists and science educators, organizations, and the public (National Research Council, 1996). The report provides content standards for students, integrated into a broader vision encompassing teaching, teacher preparation,
and other elements.3 The standards have been widely accepted as the model for the standards used in many states, though other science standards are also available, such as the online “compendium of content standards and benchmarks” developed by McREL (see http://www.mcrel.org/compendium/SubjectTopics.asp?SubjectID=2 [November 2009]).
The standards are grounded in a set of overarching principles that permeate all of the specific standards, including the premise that “science is for all students [and] that learning science is an active process, and that school science [should] reflect the intellectual and cultural traditions that characterize the practice of contemporary science” (National Research Council, 1996, p. 19). The document offers standards for teachers, professional development, and high-quality science programs, for science assessment, and for the content that students should know. The standards follow the lead of the earlier AAAS benchmarks (American Association for the Advancement of Science, 1993) in making scientific inquiry an organizing theme in the expectations for learning (see also the 2004 NSTA position statement, http://www.nsta.org/about/positions/inquiry.aspx [October 2009]). All three documents note that inquiry takes different forms in different contexts, but that it encompasses the ways scientists make observations and collect evidence, use findings to explain and predict, and engage in critical thinking. All three documents also emphasize that students must learn both the concepts and principles of science and the abilities associated with inquiry.
National Science Education Standards begins with a unifying standard that applies across grades K-12, concerning the “understanding and abilities associated with major conceptual and procedural schemes [that] need to be developed over an entire education, [and that] transcend disciplinary boundaries” (National Research Council, 1996, p. 104). The other standards are organized by age bands covering grades K-4, 5-8, and 9-12, and cover “inquiry; the traditional subject areas of physical, life, and earth and space sciences; connections between science and technology; science in personal and social perspectives; and the history and nature of science” (p. 104).
The document stresses that the standards were developed as a coherent framework and that all of their elements should be included in any curriculum that is based on them. For each content goal, the report describes fundamental abilities and concepts that underlie each standard. For example, one standard for earth and space science for grades 5-8 is that students should develop an understanding of the structure of the earth system. One of 11 fundamental concepts identified as part of that understanding is that
“The solid earth is layered with a lithosphere; hot convecting metal; and dense, metallic core” (National Research Council, 1996, p. 159).
The states also have their own standards, which, along with curriculum and assessment documents, make the performance expectations for students at particular grade levels more precise. States have also felt pressure to revise their science standards in response to the requirement in the No Child Left Behind Act, which mandated that by the 2007-2008 school year they establish assessments for grades 3-5, 6-9, and 10-12 that are linked to rigorous content and performance standards.
An assessment of states’ standards was outside the scope of our charge, but we note that they vary dramatically, and that, in general, they do not align well to national standards (Porter, 2009). States’ science standards have been the subject of various critiques that argue either that some states emphasize factual knowledge at the expense of intellectual rigor or, alternatively, that some have focused on inquiry at the expense of content (Gross et al., 2005; National Research Council, 2006). For example, according to Editorial Projects in Education (2006), 27 states had “clear, specific” standards that were “grounded in content” for the elementary grades in 2007, 32 had such standards for the middle grades, and 27 had such standards for high school. Critics have also suggested that few state science assessments address the kinds of deep understanding that science educators emphasize and have therefore had a negative impact on instruction.
Overall, there is a growing consensus that all students should be provided with a rigorous science education, in the sense advocated by the AAAS and others—that is, one that develops in-depth understanding of the most important topics (American Association for the Advancement of Science, 1991). The consensus from the National Science Education Standards and the other documents cited above is that science education should encompass:
content in the physical, life, and earth and space sciences, organized around the big conceptual ideas of the discipline;
the intellectual processes essential to science, such as inquiry, hands-on empirical investigation, use of evidence, and interpretation and analysis; and
familiarity with the nature and history of science and its applications outside the classroom and laboratory.
The NSTA, NRC, AAAS, and Achieve, Inc., are currently collaborating to develop “science anchors” to build on the existing national standards in science. The anchors will establish top priorities for science education and they are now being used as part of the Common National Standards Project (see http://scienceanchors.nsta.org/ [November 2009]).
The National Science Education Standards were developed through a consensus process that considered the views of hundreds of people—including nationally known researchers and educators, college faculty, K-12 teachers and administrators, and scientists and engineers. State standards are developed in a similar way. These documents are not the product of empirical testing of hypotheses about outcomes for students exposed to different kinds of science learning: rather, they draw on research, accounts of exemplary practice, and the contributors’ own experiences. Thus, standards are a detailed description of what the field of science education has identified as the foundation of science proficiency for K-12 students.
Learning Progressions and the Big Ideas of Science
The concept of learning progressions—descriptions of the stages of student learning—has had a significant influence on thinking about successful science learning (National Research Council, 2006, 2007; Smith et al., 2006; Corcoran, Mosher, and Rogat, 2009). This idea draws on the cognitive research (discussed in Chapter 4) that has characterized learning as entailing not just the accumulation of facts but also the developing capacity to integrate knowledge and skills for use in solving problems and responding to new situations and information. Scientific knowledge is highly structured, and there are important links among different branches of science. Thus, a critical aspect of science learning is the development of an increasingly sophisticated understanding of how one’s growing knowledge base is structured.
Primary scientific concepts—such as that the natural world is composed of a number of interrelated systems—are one of the most important organizing structures in science. They “have broad explanatory scope … and are the source of coherence among the various concepts, theories, principles, and explanatory schemes within a discipline” (National Research Council, 2006, p. 40). These primary concepts, or “big ideas,” as they have come to be called, provide a fruitful way to organize curriculum and instruction. Researchers have examined the way students’ understanding builds sequentially in a number of specific topic areas and have begun developing explicit descriptions of the stages through which understanding grows—“learning progressions.” To use an example in Systems for State Science Assessment (National Research Council, 2006, p. 45), “before students can understand that organisms get energy from oxidizing their food, they must understand that energy can change from one form to another.” These ideas allow educators to map their instruction to this empirically based model of learning. Researchers have traced learning progressions for a small number of domains; many more remain to be mapped.
WHAT INSTRUCTIONAL OPPORTUNITIES ARE NECESSARY TO SUPPORT SUCCESSFUL SCIENCE STUDENTS?
What sorts of instructional experiences can help students meet the ambitious goals described in the national science education standards? Relatively little research is available to provide definitive answers to this question. Indeed, it might be said that far more is known about the kinds of instructional opportunities that are not necessary—because the results of numerous large- and small-scale studies of science achievement suggest that they are not effective. In an overview of research on science learning, (Anderson, 2007, p. 5) noted: “researchers in science education … generally agree on one central finding about current school practice: our institutions of formal education do not help most students to learn science with understanding” [emphasis in original].
In this section we review what we found about the sorts of experiences that researchers and practitioners have identified as important to successful science learning. We look first at the guides to teaching practice included in standards documents and at other sources.
The National Science Education Standards (National Research Council, 1996) does not explicitly address the question in the way that we have framed it, but, in support of its focus on conducting scientific inquiry, the document offers many examples and details that demonstrate how students can be taught. Also useful is a supplement to the standards, a practical guide for teaching and learning that focuses on inquiry and highlights key relevant issues and research findings (National Research Council, 2000b). It identifies some relevant general findings about learning, such as that understanding science is more than knowing facts and that students build new knowledge and understanding on what they already know and believe. This report identifies several features of science inquiry in the classroom as essential (National Research Council, 2000b, p. 29):
The “learner engages in scientifically oriented questions,” for example, by posing questions for investigation, rather than answering questions generated by the teacher.
The “learner gives priority to evidence in responding to questions,” for example, by determining what constitutes evidence and collecting it, rather than being given data and instructions as to how to analyze it.
The “learner formulates explanations for the evidence,” for example, by summarizing and considering it, rather than being provided with evidence and guided in how to explain it.
The “learner connects explanations to scientific knowledge,” for example, by independently examining other knowledge resources and forming links, rather than having possible connections explained.
The “learner communicates and justifies explanations,” for example, by developing logical arguments, rather than by being given steps.
The standards also describe standards for teaching and for science programs, from which we infer that, to meet the standards, students need, in addition to exposure to all of the content standards, opportunities to (National Research Council, 1996, pp. 31, 43):
participate in a community of science learners and engage in discourse about scientific ideas; and
engage in extended scientific investigations, with access to science materials, media, and other technological resources.
The standards for new science teachers developed by the Interstate New Teacher Assessment and Support Consortium (INTASC) (2002), which are based on the national standards, provide some additional insights into the experiences science students need to have, again grounded in expert judgment rather than empirical research. For example, one core standard for beginning teachers identified by INTASC is that “the teacher of science understands and uses a variety of instructional strategies to encourage stu-dents’ development of critical thinking, problem solving, and performance skills” (Interstate New Teacher Assessment and Support Consortium, 2002, p. 4). By design, these standards echo the national standards in asserting that “multiple modes of instruction” are needed to be sure that students have the opportunity to “collect, organize and recall information, design and conduct investigations, examine assumptions, make inferences, make generalizations, present structured arguments, and apply new information to existing natural and technological phenomena” (p. 28).
The question of what sorts of instructional opportunities are necessary to foster science learning is also taken up in Taking Science to School, and this report also draws on the National Science Education Standards. It proposes that “to develop proficiency in science, students must have the opportunity to participate in [a] full range of activities” (National Research Council, 2007, p. 251), including
sharing ideas with peers;
specialized ways of talking and writing;
mechanical, mathematical, and computer-based modeling; and
development of representations of phenomena.
Because children bring sometimes naïve understanding of the natural world and scientific concepts to the classroom, the report explains, “instruction needs to build incrementally toward more sophisticated understanding and practices … prior knowledge should be evoked and linked to experiences with experiments, data, and phenomena” (National Research Council, 2007, p. 251). (This issue is discussed further below in the context of teachers’ knowledge.)
Some research that examines outcomes for students exposed to particular instructional practices and opportunities is also available. In a meta-analysis of research on the effects of teaching strategies4 on student achievement in science, Shroeder and colleagues (2007) offer limited confirmation of the consensus-based recommendations noted above. The researchers identified mostly quasi-experimental studies that included information about effect sizes or the statistics necessary to calculate effect sizes.5 Eight instructional strategies were found to have positive effects and significant (that is, unlikely to be attributable to chance) effect sizes: see Box 7-1. However, there were almost no experimental studies, and the quasi-experimental studies were limited in number: the authors found only 15 studies about information technology, 12 studies about inquiry, and 3 studies about questioning. Thus, the studies do not necessarily establish causal links between these strategies and student achievement. Shroeder and colleagues (2007, p. 1438) concluded that multiple studies have shown “that teachers have a profound effect on student learning,” but that identifying the specific factors that influence outcomes “is problematic.” For example, although there is widespread agreement that pedagogical content knowledge is a very important component of an effective teacher’s approaches, there is little research that directly links it to particular student outcomes. In part, this is because the measures of such concepts as teacher knowledge are imprecise and limited in their reliability. Moreover, research on effective science instruction tends to be small in scale and descriptive;
Science Teaching Strategies with Positive Effect Sizes
Manipulation strategies. Teachers provide students with opportunities to work or practice with physical objects (e.g., developing skills using manipulatives or apparatus, drawing or constructing something).
Enhanced materials strategies. Teachers modify instructional materials (e.g., rewriting or annotating text materials, tape recording directions, simplifying laboratory apparatus).
Assessment strategies. Teachers change the frequency, purpose, or cognitive levels of testing/evaluation (e.g., providing immediate or explanatory feedback, using diagnostic testing, formative testing, retesting, testing for mastery).
Inquiry strategies. Teachers use student-centered instruction that is less step-by-step and teacher-directed than traditional instruction; students answer scientific research questions by analyzing data (e.g., using guided or facilitated inquiry activities, laboratory inquiries).
Enhanced context strategies. Teachers relate learning to students’ previous experiences or knowledge or engage students’ interest through relating learning to the students’/school’s environment or setting (e.g., using problem-based learning, taking field trips, using the schoolyard for lessons, encouraging reflection).
Instructional technology strategies. Teachers use technology to enhance instruction (e.g., using computers, etc., for simulations; modeling abstract concepts and collecting data; showing videos to emphasize a concept; using pictures, photographs, or diagrams).
Collaborative learning strategies. Teachers arrange students in flexible groups to work on various tasks (e.g., conducting lab exercises, inquiry projects, discussions).
SOURCE: Information from Shroeder and colleagues (2007, pp. 1445-1446).
there have been very few large-scale attempts to systematically compare the effects of different instructional approaches on student achievement (Cohen, Raudenbush, and Ball, 2003).
Shroeder and colleagues also describe findings that support the general approach described in the national science education standards and elsewhere, noting that “no one strategy is as powerful as utilizing a combined
strategies approach,” and that “in an environment in which [students] can actively connect the instruction to their interests and present understandings and … experience collaborative scientific inquiry … achievement will be accelerated” (p. 1452). They also found that teaching strategies identified as innovative (as opposed to traditional), such as enhanced context, collaborative learning, and questioning strategies, had more positive influences on achievement than traditional approaches (though the researchers found no studies on direct instruction).
Other studies have examined factors that may affect science learning, such as students’ attitudes and motivation, the role of language and scientific discourse, gender and diversity, and classroom learning environments (see, e.g., Gabel, 1994; Abell and Lederman, 2007). This body of work offers intriguing suggestions about factors that may have significant effects on students’ science learning, but little that one could point to as necessary instructional opportunities.
In short, there is relatively little empirical evidence that connects the content of science standards to essential instructional opportunities or that establishes the benefits of particular types of instruction for student learning. However, there is a clear inferential link between the nature of what is in the standards and the nature of classroom instruction. Instruction throughout K-12 education is likely to develop science proficiency if it provides students with opportunities for a range of scientific activities and scientific thinking, including, but not limited to: inquiry and investigation, collection and analysis of evidence, logical reasoning, and accumulation and application of information. The opportunity for students’ learning to progress logically over time and to build the capacity to link new information to existing conceptual frameworks is also very important.
WHAT DO SUCCESSFUL TEACHERS KNOW ABOUT SCIENCE AND HOW TO TEACH IT?
The knowledge and skills students need to develop in order to be proficient in science encompass material from several academic disciplines and should be accumulated through the entire K-12 progression. Thus, an individual science teacher would not be expected to develop mastery of all of the content described in the national science education standards, but would focus on the standards for the age groups and subjects he or she intends to teach. Yet logic suggests that even teachers of elementary students need a basic familiarity with the big picture of science. Grossman, Schoenfeld, and Lee (2005) note the commonsense proposition that, “teachers should possess deep knowledge of the subjects they teach” (p. 201). It seems probable that in order to foster understanding of connections, address students’ questions and misconceptions, and so on, teachers would need to have the
confidence and competence that come with mastery of some college-level science. However, we are cautious in drawing this conclusion because no direct empirical evidence is available on this point. Nevertheless, a variety of sources offer perspectives on what effective science teachers know. We begin with standards documents published by national organizations and then consider other sources.
Professional Standards for Beginning Science Teachers
The National Science Education Standards document stresses the central importance of what teachers bring to the classroom; thus, the document actually begins with standards for teachers. The standards for teachers are framed as descriptions of what effective teachers do: see Box 7-2 (National Research Council, 1996). These standards are consistent with the kinds of objectives that have been identified as important for any teacher (discussed in Chapter 3), but they also reflect specific objectives for science learning.
The standards pay particular attention to the role of assessment as a tool for teachers to use in improving their own practice, providing critical feedback to their students, and planning their lessons. The report (National Research Council, 1996) includes standards for the use of both formative and summative assessments.6
The National Science Teachers Association (2003) has published standards for science teacher preparation that are based on, and designed to be consistent with, the National Science Education Standards. This document describes detailed standards for new teachers in science content, the nature of science, inquiry, science- and technology-related issues, general teaching skills, capacity to plan and implement a science curriculum, capacity to relate science to the community, assessment, capacity to promote safety and welfare (including proper handling of animals and materials), and capacity to sustain their own professional growth.
The Model Standards in Science for Beginning Teacher Licensing and Development, standards for beginning science teachers developed by INTASC (Interstate New Teacher Assessment and Support Consortium, 2002), are in line with the teacher preparation standards of both National Science Education Standards and the NSTA standards—and all are the product of the general professional consensus within the field of science education. INTASC’s 10 principles are listed in Box 7-3.
The three standards documents overlap and provide differing levels of detail about what new teachers need to have mastered. Davis, Petish, and Smithey (2006) conducted a content analysis of the national and INTASC
National Science Education Standards for Teachers
SOURCE: National Research Council (1996, p. 4).
standards and also reviewed 112 articles related to expectations for new science teachers. They identified five main areas in which the standards agree that teachers must have competence in order to be effective in the classroom: the content and disciplines of science, the characteristics and needs of science learners, instruction, learning environments, and professionalism (the capacity to foster their own development and be contributing members of a learning community).
These standards for science teachers are based on professional consensus and limited evidence about science teaching practices and how children learn scientific concepts and processes. They are not based on evidence that if teacher preparation programs are guided by or meet these standards, K-12 students will have higher achievement. We note, as we have elsewhere, that this approach to identifying standards for professional education is an accepted method of identifying the goals to which programs should aspire, though the lack of supporting empirical evidence reduces our confidence in conclusions about this approach.
INTASC Principles for Beginning Science Teachers
Principle 1: The teacher of science understands the central ideas, tools of inquiry, applications, structure of science and of the science disciplines he or she teaches and can create learning activities that make these aspects of content meaningful to students.
Principle 2: The teacher of science understands how students learn and develop and can provide learning opportunities that support students’ intellectual, social, and personal development.
Principle 3: The teacher of science understands how students differ in their approaches to learning and creates instructional opportunities that are adapted to diverse learners.
Principle 4: The teacher of science understands and uses a variety of instructional strategies to encourage students’ development of critical thinking, problem solving, and performance skills.
Principle 5: The teacher of science uses an understanding of individual and group motivation and behavior to create a learning environment that encourages positive social interaction, active engagement in learning, and self-motivation.
Principle 6: The teacher of science uses knowledge of effective verbal, nonverbal and media communication techniques to foster active inquiry, collaboration, and supportive interaction in the classroom.
Principle 7: The teacher of science plans instruction based upon knowledge of subject matter, students, the community, and curriculum goals.
Principle 8: The teacher of science understands and uses formal and informal assessment strategies to evaluate and ensure the continuous intellectual, social and physical development of the student.
Principle 9: The teacher of science is a reflective practitioner who continually evaluates the effects of his/her choices and actions on others (students, parents, and other professionals in the learning community) and who actively seeks out opportunities to grow professionally.
Principle 10: The teacher of science fosters relationships with school colleagues, parents, and agencies in the larger community to support students’ learning and well-being.
SOURCE: Information from Interstate New Teacher Assessment and Support Consortium (2002, pp. 14-33).
Some researchers have examined links between teacher characteristics and student learning in science. Davis, Petish, and Smithey (2006) reviewed 112 studies that examined new teachers’ practices and understandings. For the most part, the reviewed articles were descriptive in nature (most were qualitative), with discussion limited to what the teachers know and do in their classrooms. However, a few studies suggest that three areas have demonstrated effects on teacher practice or student learning.7 For example, teachers with greater content knowledge may ask more demanding questions and be “more likely to engage in sophisticated teaching practices” (Davis, Petish, and Smithey, 2006, p. 622). By contrast, those with less secure content knowledge “tended not to engage in conceptual-change teaching that accounted for and tried to address students’ initial ideas …” (p. 626).
A small number of studies also indicate that teachers who are particularly concerned about classroom management tend to be less likely to use reform-oriented teaching practices. Studies that examined the relationship between teachers’ self-efficacy and classroom practices showed that “teachers with higher self-efficacy engage students in more student-centered lessons, believe that students are capable of learning through cooperation and experiences, and develop more as science teachers” (Davis, Petish, and Smithey, 2006, p. 631).
The knowledge and practices necessary to successfully teach science are also discussed in Taking Science to School (National Research Council, 2007). The report grounds its discussion of what teachers need to know in findings from research on learning and development that elucidate the progressive nature of science learning. The authors found that students’ thinking about a given topic grows in sophistication over time and that instruction (and curricula) have generally not accounted for the ways students gradually accumulate both knowledge and understanding. In order for the concepts and reasoning with which students enter school to evolve into the science knowledge described in standards, the authors argue, teachers must understand the levels of intermediate understanding through which students need to pass.
Taking Science to School also describes a range of instructional practices that support students in developing proficiency in the four strands of science proficiency (described above), and it offers strategies for applying them with students of different ages. These strategies include, for example, designing experiments, applying theories to make sense of data,
and constructing scientific explanations and models. But the larger point the report makes is that both learning theory and small-scale studies of science instruction support the conclusion that instructional approaches that involve learners in scientific practice will naturally engage students in the specific elements of learning content and learning to think scientifically that are described in the national science education standards.
Taking Science to School also cites the limited evidence that postsecondary study of science is associated with student achievement. A 1983 meta-analysis (Druva and Anderson, 1983) found a positive relationship between student achievement and the number of science courses their teachers had taken. Monk (1994) presents data from a longitudinal survey that addressed this issue for both science and mathematics and also identified positive effects. Taking Science to School notes that it is difficult to pinpoint an “optimal” amount of coursework in science content but that the effects of teachers’ subject-matter knowledge seem to be greater for older students than younger ones. The report also notes that if college coursework were better aligned with school curricula, the effects might be more pronounced. The report presents findings from case studies that teachers with less content knowledge are less confident and effective at particular skills, such as sustaining an in-depth discussion or addressing student questions accurately and effectively (see, e.g., Hashweh, 1987; Carlsen, 1992, 1998; Sanders, Borko, and Lockard, 1993).
Taking Science to School also addresses the importance of understanding learners and learning, suggesting that teachers need to understand what students do when they learn, as well as the types of experiences that produce engagement and conceptual understanding. A variety of studies indicate that it is important for teachers to have accurate mental models of the way students learn and to understand social and other factors that may influence learning. Unfortunately, this research has yet to provide clear guidance that specific knowledge and skills in these areas are associated with benefits for students.8 Similarly, the report discusses the importance of pedagogical content knowledge, but it acknowledges that “while the logic of subject matter knowledge for teaching is persuasive, there is almost no empirical link between specialized teacher subject matter knowledge and student learning” (National Research Council, 2007, p. 305). We return to the question of pedagogical content knowledge below.
Our review of the literature uncovered very little in the way of empiri-
Another NRC report provides further elaboration of the ways students learn science and how understanding of their conceptual development is critical to effective science teaching. How Students Learn: History, Mathematics, and Science in the Classroom (National Research Council, 2005) applied to specific academic subjects the findings from an earlier report, How People Learn (National Research Council, 2000a), that synthesized recent developments in cognitive science regarding learning (described in Chapter 5).
cal evidence that particular knowledge and skills are essential for science teachers to be effective, although we note that existing research has not been designed to answer this question authoritatively. Yet, as with the instructional opportunities students need, we see a clear logical justification for the largely inference-based arguments made in standards for science teachers and other consensus documents: that to teach students the knowledge and skills required for science proficiency, teachers need knowledge and skills that are congruent with them. The field of science education has established a logical case, bolstered by some empirical evidence, that the following attributes help teachers provide students with the instructional opportunities they need to develop science proficiency:
grounding in college-level study of the science disciplines suitable to the age groups and subjects they intend to teach, which develops understanding of the big conceptual ideas in science;
understanding of multifaceted objectives for students’ science learning;
understanding of the ways students develop science proficiency; and
command of an array of instructional strategies designed to develop students’ learn the content, intellectual conventions, and other attributes essential to science proficiency, also known as pedagogical content knowledge.
WHAT INSTRUCTIONAL OPPORTUNITIES ARE NECESSARY TO PREPARE SUCCESSFUL SCIENCE TEACHERS?
With regard to our final question, how teachers might be prepared to teach in the ways we have described, there is very little empirical evidence and less in the way of consensus recommendations from the field than for our other questions.
Looking first at the limited available research, Davis, Petish, and Smithey (2006) found aspects of preparation that may support the development of effective science teachers. They found, for example, that either simple exposure to a greater number of undergraduate science courses or exposure to methods courses can build teachers’ sense of self-efficacy (confidence and sense of themselves as effective practitioners). Other studies suggest that courses that use the same general strategies advocated for K-12 classrooms—such as eliciting preconceptions, fostering inquiry—yielded teachers better equipped to use these same approaches, and that “simply requiring more science content courses is not enough to enable teachers to develop improved understanding of science content and inquiry and the nature of science” (p. 633).
With regard to teaching methods, Davis and colleagues also found some studies that suggest that for elementary teachers, training in planning, organizing instruction around important scientific ideas, and coteaching all appear to help teachers improve their attitudes toward science, boost their expectations of their students, and provide effective learning environments. They found indications that fieldwork helps teachers “develop more sophisticated ideas about science instruction and acquire self-efficacy as science teachers” (p. 635).
Lederman and colleagues (2001, p. 139) examined the effectiveness of interventions designed to “make [the nature of science] a pervasive theme throughout” a year of preservice instruction, and “to emphasize the importance of intentionally planning, teaching, and assessing students’ conceptions of [the nature of science].” A small group of teacher candidates were followed in their first experience of full-time student teaching. The authors identified four factors as having the greatest influence on these teachers’ classroom practice: their initial understanding of the nature of science, knowledge of the subject matter they taught, pedagogical knowledge, and intention to focus on the nature of science.
The National Science Education Standards (National Research Council, 1996) offers standards for professional development, which are tightly linked to those we have already discussed for student learning and for teaching. However, the report has little to say about preservice education. The report recommends that preparation for science teachers include the same elements recommended broadly for K-12 students, such as active investigations and strategies to build on teachers’ current understanding. Taking Science to School (National Research Council, 2007) also addresses teachers’ opportunities to learn through both professional development and preservice education. Like the standards, it recommends preparation designed to promote the kind of instruction it describes for K-12 students, grounded in general research on critical features of teacher preparation.
Researchers and faculty concerned with science education for undergraduate students have identified similar goals. For example, faculty from several departments have collaborated through a project at the University of California at Los Angeles to promote science education that includes hands-on research for undergraduates who are not science majors (see http://www.cur.org/publications/AIRE_RAIRE/ucla.asp [October 2009]). Though the program has the goal of promoting science proficiency for all students, it addresses the concern often voiced by the science education community, that K-12 teachers will teach as they have been taught and therefore need improved undergraduate science preparation. Similar concerns for undergraduate faculty are reflected in the goals of another program, Faculty Institutes for Reforming Science Teachers (FIRST), which engages college faculty in professional development designed to promote “active, inquiry-
based teaching” that will improve students learning (Lundmark, 2002; see also http://first.ecoinformatics.org/ [October 2009]). The program is designed to help college faculty approach their teaching in the same way they approach their disciplinary research and thus help students learn the way science is practiced (see also Handelsman et al., 2004; Ebert-May and Hodder, 2008). These recommendations and programs build on earlier work, such as reports from the National Center for Improving Science Education (Loucks-Horsley et al., 1989, 1990), which note the importance of both a strong liberal arts preparation and strong undergraduate science instruction for all teachers.
We have little basis on which to offer specific findings about what sorts of instructional experiences teachers need. It seems probable that in order to foster understanding of connections and address students’ questions and misconceptions, among other goals, teachers must have the confidence and competence that come with mastery of some college-level science, but the lack of causal evidence tempers our confidence in this conclusion. It also highlights the need for research that explores the causal nature of this relationship.
HOW SCIENCE TEACHERS ARE CURRENTLY PREPARED
Partly because the advocated approaches for teacher preparation are complex and multifaceted, it is difficult to determine whether current programs are implementing any of the ideas the field has advocated. We could find no systematic information on the content or practices of preparation programs or requirements for science teachers across the states.
We looked for data on states’ efforts to guide science teaching through either their certification requirements for science teachers or their licensure requirements for teacher preparation institutions. We found very little information about how states are using their authority to regulate teachers’ qualifications or the characteristics of teacher preparation programs, but the hints we could find provided little indication that they are taking full advantage of this authority. According to data collected by Editorial Projects in Education, 33 of the 50 states and the District of Columbia require that high school teachers have majored in the subject they plan to teach in order to be certified, but only 3 have that requirement for middle school teachers (data from 2006 and 2008, see http://www.edcounts.org/ [October 2009]). Forty-two states require prospective teachers to pass a written test in the subject in which they want to be certified, and six require passage of a written test in subject-specific pedagogy.
The Education Commission of the States has assembled information about whether or not states require that teacher preparation programs align their curricula with the state’s K-12 curriculum standards or their
standards for teachers (see http://www.ecs.org/ [October 2009]). These data (updated to 2006) show that of the 50 states, American Samoa, the District of Columbia, Guam, Puerto Rico, and the Virgin Islands, 25 require both, 6 have no policy for either, 8 require only alignment with the K-12 curriculum, and 6 require only alignment with standards for teachers.
Data on so-called out-of-field teachers, those who are not certified in the subject they are teaching, provide another indication that states are finding it difficult to ensure that all of their science teachers are well prepared. Unfortunately, the only data available are almost a decade old, although there is no reason to believe the situation has improved. The National Center for Education Statistics reports that in the 1999-2000 school year, 17 percent of middle school students and seven percent of secondary students were taught science by a teacher who was not certified to teach science and had not majored in science (see http://nces.ed.gov/programs/coe/2003/pdf/28_2003.pdf [October 2009]). Using data from the Schools and Staffing Survey, Ingersoll (2003) found that 28 percent of the teachers who taught science to grades 7 through 12 “did not have at least a minor in one of the sciences or in science education” (p. 14). Teachers of the physical sciences were significantly more likely to be teaching out of field than were biology teachers. In rural areas there are particular problems with recruiting adequately prepared science teachers, covering all science subjects, and providing adequate professional development and support for teachers in each discipline (Education Development Center, 2003). Because these circumstances are not unusual, many educators have advocated special preparation for this role, such as a degree in natural sciences that covers biology, chemistry, earth sciences, and physics. Some institutions have adopted this policy, including some in the California state university system, particularly for prospective teachers who intend to teach middle school.
These indicators provide only very indirect information about our question, however. For a more detailed look at actual course-taking patterns and other information about preservice science preparation, we had a limited amount of state-specific information. The California Council on Science and Technology (2007) conducted an analysis of career pathways for that state’s mathematics and science teachers. The report found that 9 percent of both middle and high school science teachers were teaching out of field and that even larger numbers of novice high school science teachers (35 percent) are not well prepared because the lack a preliminary credential. The percentages were highest in low-performing and high-minority schools. They also found that California lacks the capacity to meet the growing demand for fully prepared science (and mathematics) teachers and that the state is not collecting the data necessary to monitor the supply of and demand for these teachers. However, the analysis did not examine the content of science teacher preparation.
We also commissioned analyses from Florida and New York City (Grossman et al., 2008 Sass, 2008). Table 7-1 below shows the average number of science credits earned by Florida science teachers, by certification area (although the data do not provide information about the content or nature of the coursework). On average, elementary teachers earned about 13 credit hours in science and engineering, corresponding to slightly more than four courses. Secondary teachers certified in chemistry and biology earned an average of 70 and 64 credit hours, respectively, in science and engineering, corresponding to roughly 23 and 21 courses. For both elementary and secondary teachers, more than three-quarters of the science and engineering credit hours came from outside the School of Education.
The analysis of the preparation of teachers in New York City public schools (Grossman et al., 2008) included surveys of teacher preparation program completers and individuals in their first or second year of teaching about various aspects of their preparation. The surveys included items about preparation in science for elementary teachers and middle and high school science teachers.
The survey of first-year teachers in New York City included some questions about their preparation in science. The teachers were asked about the extent to which their teacher preparation program gave them the opportunity to do and learn a variety of things, such as hands-on activities for teaching scientific concepts. They rated their opportunities on a 5-point scale, with 1 being no opportunity and 5 being extensive opportunity. These teachers’ responses to several of the questions that seem most congruent with the kinds of teaching advocated by the science education community are suggestive; they are shown in Table 7-2. Although the survey was small in scale, it does suggest that New York City teachers who graduated recently from a teacher education program do not report extensive exposure to the elements advocated by the science education community.
Despite these hints, we do not have the information that would be needed to draw conclusions regarding the types of instruction and experiences that aspiring science teachers receive in teacher education programs. Therefore, we cannot tell how consistently teacher preparation programs in science draw on the converging scientific evidence regarding the teaching of science.
In our review of the literature pertaining to the preparation of science teachers we found some intriguing research, most of it carried out on tightly focused topics and on a small scale, and a compelling logical case for an integrated approach to science education—one that incorporates factual knowledge, scientific inquiry, and the nature of science. The National
TABLE 7-1 Mean Science Credit Hours, Florida Science Teachers
TABLE 7-2 New York City Teachers’ Reported Exposure to Science Preparation
Opportunity to Learn Science Education Approach
Mean Response on 1-5 Scalea
Learn hands-on activities for teaching science concepts
Learn how to facilitate student learning in small groups, such as laboratory groups
Learn how to use tasks or “discrepant events” to show how preconceptions can be incorrect
Learn how to encourage scientific inquiry
Practice what you learned about teaching science in your field experience
NOTES: Results are for teachers who attended an undergraduate teacher preparation program. See Grossman and colleagues (2008) for data on teachers who followed other pathways.
aA respondent who rated his or her exposure as a 3 would be indicating that it was roughly half-way between none at all and extensive.
SOURCE: Data from Matt Ronfeldt, University of Michigan (personal communication 2008).
Science Education Standards, now more than 10 years old, have been widely accepted and are influential, and they provide a solid grounding for this case that is bolstered by similar documents from the professional societies. The National Science Education Standards document was based on a comprehensive effort to establish consensus among a broad-based group of those with expertise and experience in science education, drawing on research wherever possible, and we see no reason to question its content. If one accepts the consensus-based standards from the field, many inferences about the knowledge and skills that will benefit teachers flow logically from its detailed descriptions of the elements of science proficiency.
Despite our concerns about the areas that have not received adequate research attention, we believe that the field has made a strong argument for the approach to science education laid out in the national science education standards. Regarding what students need to know, the field has advocated that all K-12 students receive a science education that encompasses:
content in the physical, life, and earth and space sciences;
the intellectual processes essential to science, such as inquiry, hands-on empirical investigation, use of evidence, and interpretation and analysis; and
familiarity with the nature and history of science and its applications outside the classroom and laboratory.
Regarding the instructional experiences that students need to develop proficiency in science, the consensus in the field is that students need opportunities throughout their K-12 education to engage in a range of scientific activities and scientific thinking, including, but not limited to inquiry and investigation, collection and analysis of evidence, logical reasoning, and accumulation and application of information. They need the opportunity for their learning to develop logically over time and to build the capacity to link new information to existing conceptual frameworks.
If these two propositions about what and how students should learn are true, then it follows that teacher preparation should be aligned with those goals. That is, it is plausible that the following attributes help teachers provide students with the instructional opportunities they need to develop science proficiency:
grounding in college-level study of the science disciplines suitable to the age groups and subjects they intend to teach;
understanding of multifaceted objectives for students’ science learning;
understanding of the ways students develop science proficiency; and
command of an array of instructional strategies designed to develop students’ learning of the content, intellectual conventions, and other attributes essential to science proficiency, also known as pedagogical content knowledge.
Logical though this inference is, we recognize that the cost of ensuring that teachers are prepared to meet these ambitious standards would be considerable and that the available guidance as to expectations for individual teachers is very limited. Even less obvious is exactly how teachers might best be prepared to know and do what these standards imply, as we have seen.
This is a significant problem. Current standards specify science education that can only be provided by teachers with a deep engagement in the intellectual processes of science and facility with scientific content, as well as the capacity to provide students with a variety of complex experiences with science. There seems to be a significant disjuncture between this vision and the preparation that aspiring science teachers are currently receiving. A second significant problem is that we could find so little detailed information about that preparation, so we cannot answer the question of how well current practice fits the consensus standards. We began this chapter with the observation that much is expected of science teachers in the United States; it seems to us that the U.S. Department of Education, the states, and the pro-
fessional societies concerned with the quality of teaching and with science education all share an interest in the way science teachers are prepared.
We also note that much of the available research on science teacher preparation focuses on teachers of grades K-8. Science preparation for secondary students is of equal importance and presents distinct challenges for educators. As we note above, some secondary science teachers have not majored in the science subjects they are teaching or are not certified to teach it. Moreover, it is at this stage that the curriculum for students begins to diverge by scientific discipline. Overall, there are numerous questions about the preparation of science teachers that remain unanswered.
Conclusion 7-1: Systematic data are needed on the nature and content of the coursework and other experiences that currently constitute teacher preparation in science. Research is also needed to examine the propositions regarding the teaching and learning of science contained in professional recommendations that have not been adequately examined empirically.