Dr. Richard E. Shope III, Director

World Space Foundation, Education Division



Conceptual change theory addresses the challenge of how teachers can help science learners advance from error-laden but personally relevant conceptions toward broader, deeper, and more coherent conceptions of scientific phenomena (Strike & Posner, 1992; Tobin, 1993; Hewson, 1992). The teacher’s role is to notice indicators of precursor understandings, misconceptions, emerging notions, and original ideas in order to become aware of the range of personal science conceptions that need to be addressed and then to select differentiated teaching strategies. (Karplus & Thier, 1967; Project 2061, 1993). One highly useful approach is the ED3U teaching science for conceptual change model proposed by McComas (1995). The ED3U Model offers specific strategies for teachers to guide students through a five-phased iterative process of shifting from naïve toward more advanced scientific understanding. In particular, this model highlights diagnosis as of central importance in forming a true teacher-student partnership that takes advantage of students’ personally relevant conceptions regarding science phenomena, using scaffolding strategies to guide, challenge, and move students through scientific inquiry experiences in proximal leaps toward advanced scientific conceptualization. The author is an experienced practitioner of this science teaching model, in the context of space science education programs throughout the past decade.




            Teaching for conceptual change has its roots in the post-Sputnik research and reform period, as an innovative approach that applies constructivist learning theory and responds in various ways to the situation revealed by misconception research that has shown that existing conceptions are surprisingly difficult to change (Hewson, 1992). Conceptual change research has inspired a variety of approaches that tend to share common distinguishing features. In the research literature the expression “teaching for conceptual change” refers to instructional strategies that (a) consider prior student knowledge and experience; (b) identify common misconceptions; (c) plan activities through which students shift from less accurate to more accurate understanding of science concepts; and (d) guide students to modify or create a niche for newly constructed knowledge within their conceptual ecology.

            Before instruction commences, teachers must find ways to obtain an accurate picture of students’ existing conceptions in their own context of meaning, within a totality of interconnected conceptual components, that is, their conceptual ecology (Strike and Posner, 1992). Based on diagnostic insight, the teacher designs subsequent learning experiences that are likely to result in the construction of more accurate, more expert, conceptions. This often involves dislodging misconceptions in favor of conceptions that more closely reflect the prevailing expert understanding. Successful instruction hinges on the ability of the teacher to guide students through an active process of conceptual change through which students question, discuss, and test the viability of their own ideas in ongoing and ever-evolving ways. Models of teaching for conceptual change strive to engage students in authentic learning experiences that initiate students into the way scientists think about and do science.

            The ED3U teaching for conceptual change model (See Figure 1), proposed by McComas (1995), emphasizes the centrality of diagnosing personal conceptions, for the teacher in partnership with the students, to gain insight into their existing conceptions and the dynamics of their conceptual ecologies. ED3U is a constructivist extension of the learning cycle that is sensitive to and specially designed for focusing on teaching science for conceptual change. ED3U refers to five phases through which the teacher diagnoses personal conceptions, guides exploration, mentors individual progress, challenges ideas, and scaffolds instruction for students: ED3U = Explore + Diagnose + Design + Discuss + Use.

            The premise of the ED3U model is that the teacher plays a strategic role guiding the self-regulated learner purposefully from a loosely organized system of personal conceptions toward a more informed and coherent system of conceptions connected to the world of science. Conceptual change is modeled as a selectional system, in that as students encounter a science phenomenon, they initially draw upon a diverse substrate of personally relevant ideas, then, through discussion, propose alternative explanations, and proceed to test their ideas for viability. The teacher guides students through differentiated zones of proximal development toward


Figure 1. The ED3U Model, Teaching Science for Conceptual Change


ED3U= Explore + Diagnose+ Design + Discuss + Use


Diagnosis of Personal Science Conceptions












































understanding of science concepts in the midst of active inquiry, as they work both independently and collaboratively (See Figure 2). Utilizing this framework, the teacher diagnoses the nature of the students’ personal conceptions throughout the lesson: in the midst of exploration of the phenomenon; in the midst of generating questions, making proposing explanations; in the midst of designing and carrying out investigations; and in the midst of participatory discourse that actively involves students.

            Diagnosis informs decisions, in the teachable moment, about activating or contraindicating the selection of instructional strategies from the teacher’s repertoire. Conceptual change strategies are indicated when student-generated inquiry produces several plausible explanations, likely to evoke rigorous exploration and discussion, and amenable to devising personally relevant tests of the viability of proposed explanations.

            Comparable to the widely practiced BSCS 5 E’s Model[1] (See Table 1. The 5 E’s and ED3U Compared), the ED3U model can be viewed through its underlying learning cycle structure (Exploration, Term Introduction/Concept Formation, Concept Application) in overlapping differentiated zones of proximal inquiry, as it moves through its phases:

            Exploratory Zone (E=Explore the Phenomenon), in which students explore the phenomenon, generate questions, make speculations, and propose explanations; then explore the phenomenon in a deeper way, framed by the student-generated questions and explanations in mind; teacher diagnoses by actively listening to a range of questions, speculations, and explanations to gain insight into conceptual change potential, returning questions with guiding questions.

Table 1. The 5 E’s and ED3U Models Compared



5 E’s (Bybee, 1997)


ED3U (Shope & Chapman, 2001)



Make connections between past and present learning experiences, and anticipate activities and organize students’ thinking toward the learning outcomes of current activities.




Students explore the phenomenon: in the form of a discrepant event, a visual display, a hands-on activity, an observation, or exposure to a variety of information sources, print, videos, film clips, internet sites. Object is to think toward proposing explanations of the phenomenon, selecting from a substrate of ideas.




Provide students with a common base of experiences within which concepts, processes, and skills are identified and developed.



Evoke expression of students' personal conceptions; assess how students see alternative conceptions as plausible; select strategy that brings misconceptions to student awareness; guide student to search for more accurate explanations.




Focus attention on particular aspects of engagement and exploration.  Provide opportunities to demonstrate conceptual understanding, process skills, or behaviors. Introduce new concepts, processes, or skills.




Students design personally-relevant tests of their ideas; create a context for a crucial experiment or prediction to test strength or weakness of a proposed explanation in both its explanatory and predictive value. The process of thinking out a personally-relevant test allows the students to explore the phenomenon in new ways.



Challenge and extend students’ conceptual understanding and skills. Through new experiences, students develop deeper and broader understanding, more information, and adequate skills.




Students discuss the implications. If the results suggest that a new conception is needed to replace a misconception, such alternative ideas are considered. Students may come up with their own ideas or their readiness may be open to exposure to a new theory presented by the teacher or other information source.



Encourage students to assess their understanding and abilities and provide opportunities for teachers to evaluate student progress.




Students apply new understanding; place the new conception in relation to other related knowledge; may also lead to a new cycle that further confirms or disconfirms the validity of the new conception.

            Constructive Zone (D3= Diagnose, Design, Discuss), in which students utilize scientific inquiry tools to think through their own understandings, design personally-relevant tests of proposed explanations, carry out investigations, interpret results, and discuss ideas and implications all along the way; in which the teacher diagnoses student progress, introduces scientific discourse, and guides the use of science instruments in the midst of direct encounters with the phenomenon.                 

            Application Zone (Use), in which students show evidence of putting the new knowledge to use, by communicating findings, by applying the knowledge in a new situation, by solving a new problem, by amplifying differentiated features, or by graphically reorganizing concepts into more coherent “big picture”; in which teacher and students evaluate progress.

            The ED3U model operates on the premise that encounters with science phenomena initiate impressions and activate curiosities that will quite often vary from advanced scientific understanding and this variance is inherent in the nature of scientific inquiry. Carey (2000, p. 19) asserts definitively that:

Teachers and science educators should be made aware of the important and perhaps surprising consequences of looking at the problem of science education in terms of conceptual change. For example, I have often heard teachers and science educators blame student misconceptions on faulty education at an earlier stage in the curriculum. Rather, student misconceptions are inevitable. Not having the target concepts is not an undesirable stage in students but an absolutely necessary one. Indeed, students will construct intermediate steps and misconceptions that do not conform with the views of developed science, and educators should recognize when these steps constitute progress, not problems.


This viewpoint shifts the discussion of misconceptions and conceptual change from an emphasis on what students lack in their conceptual understanding, toward understanding what students bring into the classroom as conceptual assets, taking advantage of diagnostic insights to utilize existing personal science conceptions as the rich substrate out of which scientific conceptual understanding can emerge.



Bybee, R.W. 1997. Achieving Scientific Literacy.  NH: Heinemann, p. 178-179.


Carey, S. (2000). Science education as conceptual change. Journal of Applied                                    Developmental Psychology, 21, 13-19.


Hewson. P. W. (1992, June). Conceptual change in science teaching and teacher education.                      Paper presented at a meeting on “Research and Curriculum Development in Science    Teaching,” under the auspices of the National Center for Educational Research,        Documentation, and Assessment, Ministry for Education and Science, Madrid, Spain.


Karplus, R. & Thier, H. D. (1967). A new look and elementary school science: Science                                curriculum improvement study. Chicago, IL: Rand McNally & Company.

McComas, W.F. (1995). ED3U model. Class notes taken by Richard Shope.

Project 2061, American Association for the Advancement of Science (1993).                           Benchmarks for science literacy. New York, NY: Oxford University Press.


Shope, R. and L. Chapman (2001). The Space Exploration Team Inquiry Model: Linking NASA          to Urban Education Initiatives (ASTE Proceedings).

Strike. K. A. & Posner, G.J. (1992). A revisionist theory of conceptual change. In                                Duschl, R. A. & Hamilton, R. J. (Eds.) (1992). Philosophy of science, cognitive                                   psychology, and educational theory and practice. Albany, NY: SUNY Press.

Tobin, K. (1993). The practice of constructivism in science education. Hillsdale, NJ:                          Lawrence Erlbaum Associates, Publishers.


[1] The Biological Sciences Curriculum Study (BSCS) devised the 5 E’s model, a five-step learning cycle composed of the three identifiable learning cycle features, adding emphasis at the outset to engage the students and incorporating evaluation at the end.