from Educators' eZine
Those who leave school and enter the job market in science- or technology-based industries are expected to have practical knowledge of science or technology subjects that they studied at school. Others, who go in for higher studies at the tertiary level are expected to apply lesson concepts in more complex situations within the curriculum. Besides, in today's world, most of us need basic knowledge of science and technology to operate day-to-day devices such as mobile phones. Scientific and technical literacy has become a must of for all people today. This can be achieved only by implementing effective science education programs in schools. This is one reason why hands-on laboratory experiments in Grades 9-12 science are mandatory in many school systems.
As teachers, we all know that school laboratories are places in which students are assessed not only on the theory parts of lesson concepts but also on how effectively they can perform an experiment. In many rural schools, particularly in the third world, laboratories simply don't exist despite the fact that any rural school can develop a modest science laboratory by using locally available resources, as I realized from my work in remote villages in Bhutan and Ethiopia. Although there are labs in urban schools, they don't offer opportunities for individualized learning due to reasons like large pupil intakes and quantity-oriented curriculum etc. Is there a viable solution? This article attempts to answer the question to some extent.
Thanks to rapid development in information technology, all real life situations can be simulated on your very computer screen, loaded with programs such as Java, Flash, Real media etc. With increasing number of e-learning companies and academic websites offering virtual laboratories, it is easier today than ever before, for a science teacher to use virtual lab. He simply needs to download the virtual experiment from the World Wide Web or buy it as part of an e-learning package from product manufacturers. Virtual labs can help the teacher and the taught, to a significant extent. Let us visit a few virtual classrooms.
Mr. Hailu Bekele teaches O level physics in a school in East Africa. Usually, before assigning any lab work to his kids, he shows a whole class demo. Thanks to virtual learning systems, his job is much easier than ever before, and his demo is not only enjoyable but also highly educative. He shows an experiment to measure the mass of a stone using the principle of moments. His class consists of 30 students, a laptop computer, an LCD projector and a screen. Once the students are settled down, he accesses the experiment from his computer. The first screen image displays tabs to view the following aspects of the experiment:
- Objective (of the experiment)
- Theory behind the lesson concept (Principle of moments)
- Screen shot of the apparatus (consisting of the meter-rule, pivot, a set of standard masses, the stone and thin hooks used to suspend the stone and the mass from the rule)
- "Step by step" method of doing the experiment
- Precautions needed to be taken.
The screen also contains a tab entitled "Experiment," used to begin the experiment. When he clicks it the monitor displays a visual of the full set of the apparatus needed for the experiment. He moves the "standard mass" (selected from the set) or the "stone" or both so that the "rule" is horizontal, simply by using the mouse. As he does it, the readings on the ruler are visible, and the screen looks exactly like a video shot of a live experiment. Once the meter-rule is balanced, he clicks the "Record" button located on the screen. Clicking this button enables the readings to be recorded on a separate sheet in the system. Then he clicks "Next" button. This displays the apparatus as shown at the beginning of the experiment. He repeats moving the stone and the known mass to different locations on the ruler and clicks "Record". Then clicks "Next" button. He repeats the process a few times for varying locations of the stone and the known mass. Then he clicks "Data" button to view the readings that are already recorded. Then he clicks "Graph" to view the graph related to the readings or "Calculations" to view the calculations involved. The calculations page displays the mean value of the mass of the stone computed from the readings. Alternatively, he may click "Result" button to view the mean mass of the stone.
Ms Denise Carpenter teaches middle school physics in a school in Chicago. She uses the virtual lab module consisting of an experiment to verify Ohm's law as a training tool before assigning hands-on experiments. When she opens the screen, it displays the different components of the electric circuit needed to perform the experiment. She clicks on the positive terminal of the battery. This generates the connecting wire. When she clicks on the relevant terminals of the components (battery, ammeter, voltmeter, variable resistor etc) connections are made. Once all connections are made, she clicks on the image for "switch". If the connections are correct the wires appear green in color. Otherwise they appear red. This prompts her to check the error and make correction after clicking "reset". Now that there is some current flowing in the virtual circuit, she can alter the amount of current by using the slider situated on top of the variable resistor (or at the bottom of the screen). She can set the current to any desired value and read the corresponding voltage from the screen shot of the instrument attached in the virtual circuit. She clicks "Record" to record the voltage in the database. Now that she has taken one reading she has to switch the current off (Otherwise, the wire may get heated up, in a real experiment, and lead to error in reading). She does this by clicking on the switch once again. She repeats the experiment a few more by changing the amount of current in the circuit, by using the slider. After a few readings, she clicks "Next" to move a page containing all observed data (values current and corresponding voltages) as well as calculations (Ohm's law, viz. Resistance = Voltage/Current). Next, she clicks "Graph" to display the voltage current curve of the circuit. Finally she clicks "Result" to display the conclusion drawn. Apart from these, she uses menu buttons "Precautions" and "Instructions" whenever necessary.
This kind of learning management system help not only teachers to show demos but also students to learn lesson concepts at their own pace, on highly individualized basis, before performing real time experiments.
Virtual experiments have enabled effective learning in biology without using live animals. Some state government departments of education in the US have begun offering courses in virtual dissection as a viable alternative to traditional dissection of dead animals in school labs.
Although real experiments are enjoyable by children, abstract concepts (such as earth's magnetic field, kinetic theory of matter, electromagnetic induction, photosynthesis, pollination etc) that need deeper insight can be taught only by using virtual lab experiments with high quality animations.
Although virtual experiments are a boon, they should be used as a complimentary teaching resource and never as a replacement to activity based real experiments, unless the latter involves issues of ethics such as animal dissection.
As in all other areas of science education, how best a teacher uses virtual lab in the classroom is a matter of individual interest, commitment and a willingness to learn with children.
Email:P.R. Guruprasad
