One of our goals as elementary science methods instructors is to teach students how to use the Learning Cycle. Our purpose in this article is to describe how we introduce elementary science methods students to the Learning Cycle as a teaching model. The principle that we follow is first to model the teaching we want students to eventually carry out, and then describe the characteristics of the teaching which we have modeled. Because the Learning Cycle is a guided inquiry model based on constructivist principles, we introduce students to the Learning Cycle through a series of guided inquiry activities that constitute several Learning Cycles. In short, our students first experience the Learning Cycle in action prior to a formal introduction of its rationale and structure.

In addition to achieving our primary purpose, this experience enhances students' understanding of the science concepts that form the context for introducing the Learning Cycle. Through the activities described below, we take the students through three Learning Cycles as they experience phenomena of electricity, invent definitions of closed and open circuits, apply these concepts, invent definitions of series and parallel circuits, and discuss applications for such circuits. The origins of the activities are undoubtedly in the Batteries and Bulbs unit of the post-Sputnik curriculum Elementary Science Study (Educational Development Commission, 1966). Current versions of Elementary Science Study units are now published by Delta Education.

We utilize the five-stage version of the Learning Cycle - Engage, Explore, Explain, Elaborate, and Evaluate - which was developed by BSCS for its new elementary (BSCS, 1992) and middle school (BSCS, 1994 a,b,c) science curricula. The BSCS staff refer to this version as the Instructional Model. The original Learning Cycle, developed by Robert Karplus and his colleagues for Science Curriculum Improvement Study, SCIS, consists of three stages, Exploration, Invention, and Discovery. Karplus and his co-workers (1977) renamed the three stages as Exploration, Concept Invention, and Concept Application for Science Teaching and Development of Reasoning, a set of workshop materials developed for improving high school science instruction. The stages in the Karplus models correspond to the middle three segments of the BSCS Instructional Model. The first and last stages in the BSCS Instructional Model, Engage and Evaluate, were added to the Karplus models to make a more complete cycle. The Engage stage is used to capture students' attention and determine their understanding prior to beginning instruction; the Evaluate stage is used to assess what students have learned following instruction.

The Learning Cycle in Action

Engage
Setting the stage, we tell students in this segment of the course that they will learn how to design and carry out guided inquiry science lessons according to a specific teaching model. Moreover, they will use this model to teach their lessons in class and then in their field experience sites. We tell students that we will introduce them to the teaching model by modeling it, with us as teachers and them as students.

We begin by asking the question, "What is the most difficult, least understandable area of science for you?" Responses vary, but students often name, "Physics!" We continue by asking, "What is the most difficult part of physics?" Again, a frequent response is, "Electricity!" We then dangle the bait with a challenge, "So you believe that electricity is perhaps very difficult to understand. If we can show you how you can understand electricity in a meaningful way and also teach electricity to elementary school youngsters in a meaningful way, then would you believe that you can understand and teach almost any concept in science, because almost everything else must surely be easier to understand and teach than electricity?" Again responses vary. A few students agree; most remain noncommittal. More important, we have captured their attention, and learned a great deal about their prior knowledge in science and science education, two important purposes of the Engage phase of the Learning Cycle.

Explore
Beginning this phase, we direct students to work in two- or three-person teams with a goal of arranging a D-cell, a flash light bulb, and a length of wire so the bulb lights. We distribute a D-cell, a flash light bulb with one end of a 30cm length of copper wire wrapped around its base, and several small squares of blank paper to each team. Students must draw a diagram of each arrangement tried on a separate piece of paper and label it ‘yes’ or ‘no’ as to whether or not the arrangement lights the bulb. To get them started, we often hold up the D-cell, bulb, and wire so that the D-cell does not touch the bulb or wire and ask, “Does this arrangement light the light? Here is one that you can draw and mark ‘no’.” Students spend 15 minutes trying various arrangements. We move about the room, asking questions, offering advise, and giving suggestions but few, if any, answers.

When students have exhausted their ideas for arranging and testing the D-cell, wire, and bulb, we ask for their attention and give the following direction, "One person from each team should put all the drawings marked ‘yes’ on the table marked ‘yes.’ Another member of each team should place all drawings marked ‘no’ on the table marked ‘no’." Students then go to the tables, inspect the drawings, and identify common elements among the arrangements that light the bulb or fail to do so. They spend about 10 minutes examining the drawings, searching for patterns in the data, testing questionable arrangements with their own materials, and discussing their ideas about why some arrangements light the bulb, whereas others do not. This concludes the Explore phase.

Explain
Beginning the Explain phase, we involve students in an interactive question-answer session which focuses on identifying common elements of specific arrangements which light or fail to light the bulb. Asking a series of questions, we direct them to construct a description of an arrangement which lights the bulb and to use only vocabulary that a second or third grader would typically use in a description. Two students act as vocabulary referees, judging the sophistication of the words used in the description. We write their description on the chalk board as they develop it. There is always a great deal of discussion among the students, and the referees sometimes throw out complicated words. Consequently, there is considerable modification of the description as it is developed on the chalk board. An example of a completed description is: "One end of the wire touches one end of the battery. The other end of the wire touches the yellow base of the bulb. The silver tip on the base of the bulb touches the other end of the battery."

Students agree that this is a description of an arrangement that will light the bulb. We then challenge them to develop a conceptual description based on their specific description of how the items are arranged. Students usually struggle with this task, and to get them started we ask, "What does the wire represent?" Responses vary, but someone usually says that the wire is a route or a path. We wait specifically for someone to mention the word 'path.' We then ask students to modify their first description so as to include the concept of a path. Again, students alter the original description through discussion, and we write the new description on the chalk board as they develop it, being careful not to erase the original description. An example of the revised description follows: "There must be a path around the battery from one end to the other end of the battery. The bulb must be in the path."

When we are satisfied with the description, we label it as a closed circuit, and we discuss the concept. We then ask students to explain why the arrangements on the 'no' table fail to light the bulb. They usually point out very quickly that the path around the battery is broken or not complete. We immediately write this idea on the board and label it as an open circuit. Then we discuss their definition of an open circuit as a modification of their definition of a closed circuit.

Our experiences with preservice elementary teachers have clearly demonstrated that, although they now understand a closed circuit as a complete, unbroken path around a battery and an open circuit as an incomplete, broken path around a battery, they have little or no notion as to how the bulb is part of the path. Thus, our next question is, "How is the bulb part of the path?" Usually no one knows, so we suggest that they find out by examining the close, much larger relative of their small bulb, a 40-watt light bulb. We then distribute a 40-watt bulb and a hand magnifier to each team. Each 40-watt bulb's glass is already broken so the innards can be easily viewed. We direct students to inspect the wires and to find out where the wires go as they disappear inside the base of the bulb. More discussion follows, and students point out that one wire touches the metal base of the bulb, whereas the other wire attaches to the metal tip at the bottom of the bulb. The two wires are connected above the base by a very thin wire. We sketch a drawing of a bulb on the chalk board. If the students do not identify the thin wire as the filament, then we do so. Students use hand magnifiers to verify that their small bulb is built like the larger one. At this point, students are able to point out the path of wires through the bulb and to explain why the metal base and tip of the bulb are part of the path. This concludes the Explain phase. Perhaps 45 minutes have elapsed since this phase began.

Thus far, we have focused on introducing closed and open circuits as we, or they, may do in an elementary classroom. At this point, we redirect the focus toward the Learning Cycle as an instructional model by asking, "Why did we use the past 60 or so minutes to introduce closed and open circuits when we simply could have directed you to read the definitions of closed and open circuit in a science textbook? Reading the definitions and then discussing them might take perhaps 10 - 15 minutes. Why did we spend all the extra time?" Students usually point out the need to utilize hands-on science activities to introduce processes and concepts to elementary school students. They frequently mention Piaget's theory and point out how much more interesting hands-on instruction is for youngsters. We ask, "If the meaning of closed and open circuits did not come from a textbook, then where did the meaning come from?" In the discussion that follows, the students acknowledge and reflect that they constructed the meaning through their activities with the D-cell, wire, and bulb as well as their discussions. At this point they often express an awareness that we, as teachers, were guiding them toward that end, but they did not realize it during the lesson. We always point out that we only supplied the terms 'closed circuit' and 'open circuit.'

Our next series of questions focuses students' attention specifically on their role as students and our role as teachers during the Explore and Explain stages of the Learning Cycle. We ask, "What did we as teachers do during the light-the-bulb activity? Also, what did we not do?" Students typically point out that we asked a lot of questions and listened to them. Also, we encouraged them to keep thinking, try new alternatives, and talk to one another. They note that we did not answer their questions, give definitions, or put words into their mouths. Then we ask, "What did you as students do? What did you not do?" Students respond that they talked, explored, asked each other lots of questions, laughed, and struggled. Also, they point out that they sometimes became frustrated and embarrassed when they could not light the bulb, and then became excited when they were successful. Students tell us that they did not receive much information from us and did not listen to lectures, memorize definitions, or read boring books. We then repeat these questions, asking students to focus on teacher and student roles beginning with the inspection of the drawings (start of the Explain phase) and ending with the introduction of the terms 'open circuit' and 'closed circuit (end of the Explain phase).' Regarding teacher roles, students point out that we encouraged them to explain ideas in their own words. Also we continuously referred to actions and data, not abstract concepts, in asking our questions. Regarding student roles, students respond that they described and explained their ideas to each other and to us, used the activities to develop explanations, and did a lot of difficult thinking and reflecting.

Emerging from this discussion are students' descriptions of teacher and student roles for the Explore and Explain stages. At this point we introduce the term 'Explore' in terms of student and teacher roles during initial light-the-light activity, then define it as experiences which provide a foundation for developing students' comprehension of a concept. Then we introduce the term 'Explain' in terms of student and teacher roles during its specific activities and define it as the stage following Explore in which the teacher clarifies the concept and introduces vocabulary terms associated with the meaning of the concept.

At this point, we return to our initial question about electricity being such a difficult idea to understand. We often ask, "Have you learned anything new about electricity?" Many students respond that they did not understand circuits or how light bulbs work until now. Next we ask, "What did you think about our challenge that if you could understand and teach electricity, then you could understand and teach almost anything in science?" Students often reply that they thought we were joking, that there was absolutely no way that we, or anyone, could make electricity comprehensible. We then often ask, "OK, but did we get your attention?" Students usually reply that we did and frequently offer one of two reasons. They state that they were intrigued by the challenge regarding electricity or that they knew that they must design and carry out inquiry science lessons. At this point, we introduce the term 'Engage' for first stage of the Learning Cycle, define it as an event or question related to the concept that the teacher plans to introduce. Next, we review and discuss the Engage, Explore, and Explain stages in terms of their sequence, the questions and activities done thus far, and the appropriate as well as inappropriate teacher and student roles in each phase. Finally, we introduce the term 'Learning Cycle' and define it as a five-stage instructional model. We point out that we have already modeled the first three stages. Two more stages remain to be modeled.

Elaborate
As a transition, we ask students to speculate as to what the nature of the yet-to-be-introduced stages could be. A good question is, "Thus far, we have captured your attention in Engage, provided you with a concrete, activity-based foundation for developing the concepts of closed and open circuits in Explore, and clarified the meaning and introduced the term for the concept in Explain. What other elements of high quality teaching and learning have we not yet done and could be carried out following Explain?" Students' most common response is the application of newly introduced concepts to familiar, everyday situations. At a more general level, students express a keen interest in using science to address and solve individual, communal, and societal problems. We capitalize on their comments and point out that teaching students how to apply knowledge to new problems, although often taken for granted, is a fundamental goal of science education. We emphasize that, if application of knowledge is an important goal, then as teachers we must teach specifically for application of knowledge. Moreover, we note that they have just described the next stage of the Learning Cycle, and we introduce the name Elaborate, identify it as the stage following Explain, and define it as a set of experiences for building students' understanding of concepts by applying the concepts to new situations.

At this point, we refocus students' attention on the application of closed and open circuits, saying, "As we proceed through the next activity, reflect not only on the application of circuits, but also on the characteristics of this activity in terms of its place in the Learning Cycle." We distribute a file folder to each team. The folders have six metal notebook brads (labeled A,B,C,D,E,F respectively) sticking out as shown in Figure 1. The folders are taped shut so that they cannot be opened easily. We tell the students, "The metal brads may be connected by wires in some manner inside the folders. Work in your team to test for connections with your D-cell, bulb, and copper wire. Record your data for each possible connection on a piece of paper. Develop a model of a circuit diagram based on your data and draw the diagram on a piece of paper." Students must use their newly constructed concepts of closed and open circuits to do this task. They typically spend about 10 - 15 minutes collecting data and developing a circuit diagram. We move about the room, again asking questions, offering advice, and giving suggestions but not answers.