Teaching Symbiosis by Use of Scientific Inquiry Methods:
Exploring the Possibilities and Pitfalls
National teaching standards stress the importance of using inquiry methods to teach children science. (NRC 1996). To effectively use these methods, teachers must understand the mechanics of the instructional strategies and maintain a firm grasp on how to best implement them. This paper examines the ways research-based inquiry methods can be utilized to teach students about symbiotic relationships occurring in nature. It also examines the challenges, complications, and potential difficulties faced by science teachers using these instructional methods.
What are Inquiry Teaching Methods?
Inquiry is a teaching strategy that allows students to inquire into authentic issues or questions arising from their own experiences. Some researchers and educators have noted confusion about inquiry strategy, how it is accomplished, and what it involves. (Martin-Hansen 2002). In the interest of clarity, it may be helpful to start with definitions of terms.
Inquiry has been described as the natural way children learn about the natural world, by learning from activity, problem-solving, and discussing questions with others. (Crawford 2000). When doing inquiry projects, students are observing facts or events, accurately and systematically; recording and representing data properly; identifying and controlling variables; using analytical tools like computers to handle data; identifying questions or propositions to be investigated; developing scientifically-sound explanations of events they have noted; and analytically assessing the relationships between observed facts and explanations. (Trumbull et al. 2006). In its simplest form, inquiry can be defined as a process of active learning, where students answer questions by analyzing data. (Bell et al. 2005).
Four levels or types of inquiry instruction have been identified. The four levels are open inquiry, guided inquiry, coupled inquiry, and structured inquiry. In open inquiry, the highest level, students pose their own questions, design their own experiments, and communicate their results. It is the approach most like the work of actual scientists. In the second type, guided inquiry, teachers help students design their experiments. The teacher may, for example, propose a question to be investigated and provide materials to be used. Guided inquiry teaches skills and provides students with the background experience to support their eventual use of open inquiry methods. The third level, coupled inquiry, combines open and guided inquiry, using a cyclical approach. The teacher first chooses a question for investigation and poses it as an invitation to inquiry. The invitation is followed up with guided inquiry led by the teacher, and a subsequent open inquiry initiated by students. The inquiry is eventually resolved, and some form of final assessment of the process is conducted. In the fourth type of inquiry instruction, structured inquiry, the teacher designs and directs the experiment. Some refer to structured inquiry as “cookbook science,” where students are simply following written instructions rather than actually engaging in meaningful science. (Martin-Hansen 2002).
The levels can be viewed on a continuum. Students cannot be expected to achieve the highest level (open inquiry) without first working up the scale, starting with the lower level teacher-controlled lessons and eventually conducting student-initiated experiments. Many students require gradual introduction to the inquiry method before they are capable of developing their own research questions and identifying effective ways to collect data to address their questions. (Bell 2005).
One alternative way to illustrate the scientific inquiry process is by use of design briefs in classrooms. In a design brief, a scientific question is pointed out, explored, and analyzed. Again, the students require some prior knowledge of scientific methods and concepts. A design brief is essentially a type of open inquiry, according to the proponents of the method, where the brief is organized for students in a four-part format. The teacher provides a general context statement (providing perspective), followed by a plausible scenario (a story to set the stage), and a challenge (where students are asked to resolve a problem), in light of some defined limitations and rules. (Gooding et al. 2007).
Inquiry techniques can be effectively used across disciplines, not solely in science classrooms, as one way to help students apply their understanding of particularly important concepts. (Marzano et al. 2001).
What are the Challenges or Complications Facing Teachers Using Inquiry Methods?
Inquiry is an instructional method which may be easier discussed than meaningfully accomplished; in other words, it might be easier said than done. Students cannot be expected to successfully complete inquiry projects without previous exposure to the method. Inquiry projects tend to take more classroom time and educators’ energy than other instructional methods. Teachers using inquiry in the classroom must have the necessary attitude toward science, aptitude for helping students conduct experiments, and understanding of the subject matter. The success of projects and results can be unpredictable, and assessment of student learning can be a daunting challenge for educators.
While this instructional strategy is often referred to as “research-based,” collecting data regarding its effectiveness does not appear to be a simple task. Classrooms are complex environments, and it is evidently difficult to conduct studies in those environments that actually and accurately assess learning and, consequently, effectiveness of the methods.
Teaching Science Process Skills
From a purely practical perspective, students cannot be tossed into inquiry exercises without skills. Doing so would be like tossing a child into a lake without bothering to teach her to swim. Successful use of the inquiry method requires an understanding of basic skills, which could be taught in manageable blocks using more explicit methods (such as direct instruction), are set out in Table 1.
(table omitted - didn't paste to Wiki! well.)
Table 1: Science skills and tools which must be taught before students can engage in successful inquiry projects (adapted from Wilke 2005)
Students are more likely to learn from inquiry lessons when they understand the elements of the process. Educators must ensure their students have sufficient foundation before they embark on inquiry projects. Investigative skills must be nurtured and developed with purpose, thought, and careful planning. (Pellathy et al. 2007). The success of students’ projects may depend, in large part, on the experience and beliefs of their teachers.
Impact of Educators’ Attitudes and Aptitudes
Students must understand certain skills to learn by inquiry; educators must master them to teach it. Inquiry instruction is not effective unless the adult in the classroom handling students’ questions and assisting with hypothesis formulation and data analysis fully understands the method and the subject matter content. The teacher must be a subject matter expert and must be confident and capable in the nuances of inquiry. (Trumbull 2006).
Research has addressed teachers’ views on the nature of science, and the impact of those views on how effectively they use inquiry methods. Regarding views on the nature of science, according to one study, there is no single, unitary view of the nature of science, but there is general agreement among teachers about several primary tenets: knowledge of science is gained by experimental or empirical research and therefore cannot be seen as final or irrevocable; observations are based in theory and claims are based in inference; working in science allows exercise of imagination and creativity. (Trumbull 2006). While an accurate understanding of the nature of science is crucial to an inquiry lesson, it does not necessarily guarantee successful implementation in the classroom.
Teachers’ views on the nature of science were classified by researchers into two categories, the distal and the proximate. Distal knowledge was defined as the accepted, declarative knowledge of science held by society and scientists generally. Proximate knowledge of the nature of science was viewed as more individualized and student-based, taking into account students’ life experiences, beliefs, and personal commitment to learning science. (Hogan 2000). Not surprisingly, in the study of teachers who hold the differing views, it was reported that the educator holding the proximate, student-based view the nature of science was more effective in implementing student-driven inquiry projects. (Trumbull 2006).
Another study explored the methods used by one teacher, and attempted to identify the elements of his teaching style that led to effective inquiry projects in his classroom. (Crawford 2000). The instructor used inquiry successfully because he could effectively collaborate with others, especially with students and members of the community who play varying roles in varying circumstances. When an inquiry project addressed a real, authentic problem in the community, students took responsibility for the success of the project and ownership over it. The study illustrated how a teacher must be more than a facilitator. He must model the role of scientist during the inquiry project, and must help engage students in asking questions, formulating hypotheses, designing and redesigning investigations, struggling with sometimes-problematic data, making and rejecting inferences, and devising and revising theories. (Crawford 2000). Some studies also noted the lack of research that has actually addressed and examined teachers’ practices in inquiry classrooms. (McNeill and Krajcik 2007; Flick 2000).
Teachers who are using truly student-based inquiry methods have taken on serious responsibility. When it works, it results in an authentic “I am a scientistic!” experience for the students. When it does not work, it can result in a frustrating, chaotic, uncontrolled classroom with little learned or accomplished. It appears that the distinction may lie in the teacher’s level of commitment to making inquiry lessons effective, and willingness, on the part of the school, its administrators, and the community, to participate.
Difficulty in Assessing Student Learning and Achievement
In a traditional classroom, learning can be measured by administering tests and counting correct answers. In a classroom using inquiry instruction, assessment becomes a more challenging prospect. From a practical perspective, the question becomes: what other methods might allow teachers to assess what students have learned about the subject matter and the nature of scientific inquiry?
It has been suggested that assessment is necessary to determine the extent of student learning for the purpose of planning future instruction, rather than simply about making judgments on the quality of the students’ work. Since inquiry is a fluid learning process, assessment and communication between teacher and student must be more frequent and informal. (Peters 2008). Some form of journaling, perhaps two-way, is recommended. How it is accomplished may depend on class size and time constraints. Instructors can avoid making impractical or unfair judgments about student accomplishments by allowing some measure of student self-assessment, or by developing ways peers can assess or provide feedback to each other. Lessons must be carefully and thoughtfully planned, with assessment mechanisms designed to allow students to show what they know. Assessment must vary depending on circumstances. (Peters 2008).
A factor further complicating matters is the need to ensure state or school district standards and benchmarks are met for each grade level. In the current era of the standardized test, teachers have an obligation to address basics. The question is how successfully the basics can be taught using inquiry methods.
How May Inquiry Teaching Methods Be Effectively Used to Teach Symbiosis?
The complications and pitfalls of using inquiry notwithstanding, the possibilities of engaging students in real science, with a purpose, are endless. Those possibilities include using inquiry lessons about symbiotic relationships, which are ubiquitous in nature but not explicitly addressed in instructional strategy research. (Case 2003).
Symbiosis, in its broadest sense, has been defined as a prolonged relationship between at least two organisms of different species, lasting during the entire existence of at least one of the symbionts. The complex associations can range from antagonistic to cooperative – with parasites or pathogens harming the host (on the antagonistic end of a spectrum), mutualistic symbionts both benefiting (on the cooperative end), and commensalists benefiting while other organisms involved in the relationship are not hurt (somewhere in the mid-range of the spectrum). Such relationships are dynamic in nature and occur everywhere. They are found, for example, on the dark ocean floor where giant tube worms with no digestive systems root themselves near hydrothermal vents and derive all their food from chemosynthetic bacteria living in their vascular tissue; in warm, tropical waters where photosynthetic algae live and produce nutrients inside the cells of corals; in the roots of most legumes where bacteria live and provide nitrogen-fixation services that allow the plant to efficiently synthesize amino acids; and in the guts of animals and insects where microorganisms help break down cellulose, synthesize vitamins, protect against pathogens, and even, in the case of certain nematodes, kill the larvae of other insects, so the nematode can use the dead larvae as soil to farm more microorganisms which the nematodes n turn feed upon. (Dimijian-1 2000).
Biologists believe that much of the diversity in nature resulted from symbiotic relationships, which caused organisms to change over time and through the process of evolution. (Dimijian-2 2000). They also believe that cellular organelles, specifically chloroplasts and mitochondria, were once free-living organisms involved in symbiotic relationships. Over time, the organisms were essentially absorbed by their hosts and now provide the energy source for all plants and animals. (Case 2003; Dimijian-2 2000). While symbiosis has traditionally been addressed in classrooms and curriculums within the context of explicitly-taught ecology lessons (Case 2003), science teachers should contemplate how implicitly-taught inquiry lessons could effectively address the topic.
Case Studies and Inquiry Laboratory Lessons: Nematodes and Mistletoes and Rotifers, Oh, My!
Educational researchers have attempted to test the success of inquiry methods. In 1995, one researcher concluded that previous studies showed mixed results in inquiry classrooms, and noted that results improved with higher functioning students, better trained teachers, and supportive educational environments. (Flick 1995). Another study published more than a decade later asserted that research explicitly examining the impact of inquiry instruction practices on student learning was still lacking. That study focused on thirteen chemistry teachers using one inquiry-based lesson, designed and provided by the researchers. While they generally reported gains in student understanding of scientific inquiry, variations among the teachers’ practices distinctly influenced the extent of students’ success. They reported improved results when teachers, during introduction to the lesson, explicitly explained the rationale underlying scientific explanation. The students had been given a useful understanding, from the outset, of the logic underlying the project. (McNeill 2007).
A year-long study of the methods of one successful teacher was intended to provide a model for teachers doing inquiry projects, especially as how they should interact with their students. The study’s author concluded that successful inquiry projects are the result of collaboration between the teacher, the students, and the community. The model constructed in the study included six elements – the collaboration, teachers modeling scientists’ behaviors, and students addressing problems authentic to them, focusing on and wrestling with their data, connecting to society, and developing ownership of their projects. (Crawford 2000).
Another study described by its authors as “quasi-experimental” was intended to compare achievement of students who received instruction using inquiry with a control group taught by traditional direct instruction. Students taught inquiry did not test higher on factual knowledge, but did better on comprehension (testing understanding of concepts) and on integrated test items (applying solutions to appropriate situations). Utilization of the hands-on inquiry method arguably enriched the students’ learning experience, but did not improve their retention of the factual material. (Mao et al. 1998).
Materials are also available, albeit somewhat limited, to guide and inspire teachers interested in conducting inquiry-based laboratory lessons. Many of those materials are in found in magazines written by and for science teachers; a few articles specifically focus on using inquiry to illustrate symbiotic relationships. In one of the articles, the relationship between parasitic nematodes and host insect larvae was examined using open inquiry. In this hybrid lesson plan and research paper, students posed their own questions, designed individualized experiments, collected, recorded, and analyzed their data, and developed conclusions. At the end of the exercise, students presented their findings to the class. The researchers statistically assessed the success of the laboratory exercise by administering pre- and post-lesson tests. While there may be some question about the validity of the assessments due to the evidently subjective manner in which they were scored, the results generally indicated that students’ critical thinking skills improved, as did their understanding of scientific method and experimental design. (Bliss et al. 2007).
Nematodes were used in another published laboratory exercise which illustrates how structured inquiry might be used to test evolutionary theories regarding populations. This laboratory exercise proposes that students study and compare the growth rate of populations of different strains of the soil nematode Caenorhabditis elegans. The nematodes are grown on culture plates, data regarding population change is recorded, and students make observations about how the strains fared in reproduction and competition for resources. Eventually, students must determine whether Darwin’s evolutionary premises are illustrated by exponential growth of the populations, noting the impact of limited resources on population growth and the competitive advantage enjoyed by some strains as compared to others. (Mueller 2007).
Mistletoe (Phoradendron serotinum) is a parasitic flowering plant that uses a host tree to supply its minerals and water. It is used as a model organism in a guided inquiry exercise that proposes collaboration between secondary students and Georgia Southern University scientists. The scientists pose ecological questions to be investigated, and students collect the data actually used to address the questions, share their data by posting it to a website, reach conclusions based on the data, and present their results via the website. If participation in this particular program is not feasible because of location, the authors suggested teachers contact science departments of nearby colleges or universities to explore the prospect of using students to help collect data for similar collaborative studies. (Leege et al. 2008)
Another article suggests using desiccated rotifers to illustrate the steps of scientific process. Rotifers are complex microscopic organisms that can survive in extremely dry environments by entering anhydrobiosis, a state of dehydrated suspended animation. The article explains how water samples likely to contain these organisms can be collected, observed, and used to illustrate the process of scientific thinking. Students ask questions about where the organisms came from, and hypotheses are proposed. The instructor suggests one of the hypotheses, the idea that some organisms can survive in dry conditions and revive from a dormant state when water is present, can be tested. The students design and conduct an experiment where dry silt collected from a sometimes damp drainage ditch (or similar environment) is hydrated, the results analyzed by observation of the rehydrated organisms, and conclusions reached. Scientific theories are then developed by inductive reasoning. (Clopton 2008). Additional articles address how inquiry might be injected into vertebrate anatomy labs (Meuler 2008) and photosynthesis lessons (Salter et al. 2008).
All these examples illustrate the diverse ways inquiry instruction could be effectively used to illustrate the amazing diversity of life on this plant and to demonstrate interactions between organisms involved in symbiotic relationships. The possibilities in any given science classroom are limited only by its teacher’s lack of experience, creativity, and knowledge of scientific process and subject matter. Ultimately, an educator must be willing to collaborate with his students. The result may be a “symbiotic” relationship between the student, the teacher, and their community, where all benefit.