We are now in an era where computers are as common in classrooms as chalkboard and desks. Students, parents, and the community at large now expect computers to be used as tools in instruction, much as they have traditionally expected textbooks to be at the heart of the classroom routine. This is an expectation that has only developed over the past twenty years. Our problem as educators is how do we integrate computers into our instructional practices to maximize student learning?

** A Proposal **

Iâ€™m proposing a teaching model for integrating computers into science instruction, the area with which Iâ€™m most familiar. I trust those of you who are more familiar with mathematics, social studies, or language arts can adapt this model to your specialty area too. To build the idea for this instructional model, lets first consider the generally accepted goals of science teaching. We want our students to become scientifically literate. This means, in a nutshell, that they have an understanding of a diversity of science concepts. The next consideration that goes into creating the model is how students build science concepts. That is, how do they best learn? Research in the area of science teaching shows that concepts are constructed and refined by students based on first hand observation and interaction with phenomena, testing prior knowledge and beliefs against these interactions, and collaborating with peers in these processes. Especially for elementary and middle school students, actual hands-on, minds-on, doing science has been the gold standard for teaching practice.

Now the question is if and how computers can enhance this gold standard of science teaching practice to make it platinum. The tentative answer to the first part of this question is yes, computers can be used to enhance the already effective hands-on inquiry approach to science teaching. Meta-analyses of studies of the effects of using computers in science teaching support this contention. The second part of the question as to how computers can be used with hands-on inquiry calls for a model of instruction that recognizes the advantages of computer-based instruction in this context.

** The C4E Model **

I propose and describe here a computer-assisted hands-on science-inquiry teaching model called the C4E model — Computer Enhanced Exploration, Explanation and Extension. It is based on the learning cycle, a well-established and widely recognized approach to science instruction used in nationally recognized curricula such as the Full Option Science System and the Science Curriculum Improvement Study. The C4E model Iâ€™m proposing incorporates the best practices of hands-on science teaching and learning with the advantages offered by online resources such as visuals and computer simulations.

During the first part of a C4E lesson, the Exploration, students work in collaborative groups to explore the lesson concept hands-on. As the teacher, you guide the groups in their exploration of the lesson concept by asking guiding questions to encourage observations and interactions with the actual phenomena being studied. For example if your class is studying simple electrical circuits, give each group a battery, bulb and wire and ask them if they can make the bulb light. How many ways they can make it light? Have them make drawings of ways that do and ways that donâ€™t work. Have them add another battery, a switch, or a resistor to their system and observe and record what happens. Exploration offers the advantages of hands-on interaction with objects and systems. Students work with and get the feel for real materials and how they interact in the face of guiding questions from the teacher and peer discussion. Such experience is fundamental to conceptual development, especially for elementary and middle school level learners.

Concept Explanation is the second part of a C4E lesson. As the teacher ask questions to the class about what they observed and what it means. For example, did they get the bulb to light and if so how? How many different ways did they find to get the bulb light? What happened when they added another battery, a resistor, and a switch? Ask the students what concept they are studying. Identify and define the concept as a _circuit_ and list associated vocabulary words and phrases. At this point your first computer enhancement of the lesson can come into play as you show students examples of different circuits and circuit components from images found on the Internet. You can show them that circuits come in many configurations and serve many purposes.

Concept Extension is the final part of the C4E lesson in which students show they can extend their understanding of the lesson concept, in this case circuits, to a variety of applications and in a more abstract form. This part of the lesson can be used as both additional student practice and for assessment. The concept extension is where you can really leverage the power of computers and the Internet as learning tools. In particular I like to have student groups use concept simulations to extend and test their understanding of the lesson concept. A search of the net will yield a number interactive circuit simulation ranging from simple to complex. Some of them require JavaScript to be enabled. One such is Sean Russelâ€™s Interactive Voltage Simulator, also available at Welcome to the Voltage Circuit Simulator. The real power of simulations as learning tools comes from the fact that variables in a system can be changed quickly and predictions or hypotheses can be immediately tested. Very quickly students can determine if they do or do not understand a concept. During this C4E lesson students will have progressed from learning the basics about circuits through concrete hands-on investigations to testing their conceptual understanding of circuits in an abstract sense with online simulations. With such a lesson you are certainly reaching for the platinum standard of teaching practice.

When I taught the C4E lesson I discovered that the students responded positively to the combination of hands-on investigations with simulations. They commented that the hands on "exploration" gave them a real context for the simulation "extension" part of the lesson, while the simulations gave them them a chance to quickly build and test many different kinds of circuits. The students all expressed a preference for a lesson that combined hands on investigation with simulations (as the C4E does) as compared to a hands on only or simulation only lesson. As a teacher I was impressed with how engaged the students were when working with the simulations. Note that we used the Ohm Zone on line simulation during this lesson.

** Summary **

There are many variations of course on how computers can be integrated into a C4E lesson. I have provided here but one brief example. In general start the science lesson with hands-on investigation of some object, system or question. Have students work together to answer questions or solve problems about the object or system under study. First-hand study and collaboration are essential to science learning. Next move to explaining the phenomena under study using vocabulary and internet-based visuals to support you and your studentsâ€™ explanation of the lesson concept. Finally move to the virtual world of Internet-based simulations of the lesson concept to allow to students to extend and thoroughly test their concept understanding.