Computer-Based Exploration

Computer-Based Technologies in Science Education

Computer-based technology is revolutionizing science education.  According to Roschelle, Pea, Hoadley, Gordin, and Means (2000) computer-based technologies are having a positive impact on the way students learn scientific concepts and skills. Specifically, computers facilitate active, constructive learning experiences.

Certain elements make learning effective. Roschelle et al. (2000) name the following four fundamental elements of effective learning that are based on cognitive research:

1. Active engagement

2. Participation in groups

3. Frequent interaction and feedback

4. Connections to real-world contexts. (p. 79)

Integrating technology into science education provides a context for these four fundamental principles, especially when embedded into cooperative learning activities. In order to show how technology enhances science education, we have included numerous examples of experiments with links that can serve as a foundation for cooperative learning using computer-based technologies.

Reference

Roschelle, J. M., Pea, R. D., Hoadley, C. M., Gordin, D. N., & Means, B. M. (2000). Changing how and what children learn in school with computer-based technologies. The future of children, 76-101. Retrieved August 22, 2014 from http://halshs.archives-ouvertes.fr/docs/00/19/06/10/PDF/A103_Roschelle_etal_01_Packard.pdf

compact disc (also known as a CD) (If you don't own any CDs, you can buy an old one at a garage sale. Or ask at a record store if they will give you a CD that won't play.) sunshine (or a bright flashlight and a room that you can make dark) piece of white paper

Take the CD out of its case and take a look at the blank side (the side that doesn't have any printing on it). You'll see bands of shimmering color. Tilt the CD back and forth and the colors will shift and change.

Hold the CD in the sunshine. Or if it's a cloudy day, turn out the lights and shine your flashlight at the CD. Hold your piece of white paper so that the light reflecting off the CD shines onto the paper. The reflected light will make fabulous rainbow colors on your paper.

Tip the CD and see how that changes the reflections. Change the distance from the CD to the paper. What happens to the colors?  Take a close look at your CD. It's made of aluminum coated with plastic. The colors that you see on the CD are created by white light reflecting from ridges in the metal.

When light reflects off or passes through something with many small ridges or scratches, you often get rainbow colors and interesting patterns. These are called interference patterns. Here are several other ways you can see interference patterns. Squint at a distant bright light at night. You'll see starburst patterns around the light. If you look closely, you can see colors in the patterns. These patterns form when light bends around your eyelashes and imperfections in the layers that make up the lens of your eye. Tilt your head to one side while watching the pattern and notice that the pattern moves with you. In a dark room, look at a bright light (maybe a candle flame) through a nylon stocking, a silk scarf, a feather, or a tea strainer. The pattern that you see depends on what you look through. Move the thing you're looking through and notice that the pattern moves with it. Buy a set of "rainbow glasses" in a toy store or a science shop. Through these glasses, all lights look like rainbows. The glasses are made with diffraction gratings, clear plastic that is etched with many lines.

Why does a CD reflect rainbow colors? Like water drops in falling rain, the CD separates white light into all the colors that make it up. The colors you see reflecting from a CD are interference colors, like the shifting colors you see on a soap bubble or an oil slick. You can think of light as as being made up of waves-like the waves in the ocean. When light waves reflect off the ridges on your CD, they overlap and interfere with each other. Sometimes the waves add together, making certain colors brighter, and sometimes they cancel each other, taking certain colors away.

              

lens-like the one in a magnifying glass or one from a disposable camera room that you can make very dark light source-like a TV set or a brightly lit window sheet of white paper    Look through your lens at these words or at your fingertip. Do things look bigger through your lens? If they do, your lens is a magnifying lens. It will work for this experiment.  Go into a room that has just one source of light. On a sunny day, a window works just fine. (Turn off any electric lights in the room.) At night, you can turn on your TV set and use it as a light source. You're going to use your lens to make a picture of the light source. So you want a light source that will make an interesting picture. A picture of an ordinary lightbulb is just a round spot, which is pretty boring.  Stand a few feet away from your light source. Hold your lens up so that light can shine through it. Hold the piece of paper on the other side of the lens so that light shines through the lens and onto the paper. The paper is your screen-like the screen in a movie theater. The paper screen will reflect a picture made of light so that you can see it.   Start with the lens up close to the paper, and slowly move it away from the paper and toward the light source. Watch the pattern of light on the paper. When the lens is the right distance from the paper, you'll see a picture of the light source. The picture will be upside down and backward.  If you don't see a picture right away, keep trying. Try standing closer to the light source. Or try moving the lens farther from the paper. It may take some experimenting, but sooner or later you'll get a picture. When you use your lens to make a picture of something that's brightly lit, you are doing the same thing that a movie projector does. In a movie projector, a light shines through a transparent picture, then through a lens. The lens takes the light from the picture and makes a big picture on the movie screen. Warning You may already know that you can use a lens to focus sunlight into a very bright circle. That circle can be hot enough to start a fire. For many kids, playing with a lens outdoors can be like playing with matches. Take appropriate precautions. If you take a lens outside and use it to focus a circle of sunlight, DON'T stare at the bright spot. That spot of light is an image of the sun. You can hurt your eyes by staring at it, just as you can hurt your eyes by staring at the sun. empty Pringles® chip can marker ruler X-Acto knife or utility knife (ask a grown-up to help you cut) thumbtack or pushpin masking tape aluminum foil scissors (if you want) bright sunny day    Take the plastic lid off the Pringles® can and wipe out the inside. (Save the lid!)  Draw a line with the marker all the way around the can, about 2 inches up from the bottom. Have a grown-up cut along that line so the tube is in two pieces.  The shorter bottom piece has a metal end. With the thumbtack, make a hole in the center of the metal.  We're going to use the plastic lid as a screen. If your lid is clear, you may need to apply a piece of wax paper, white tissue paper, or vellum to the lid to act as a translucent screen. Put the plastic lid onto the shorter piece. Put the longer piece back on top. Tape all the pieces together. To keep light out of the tube, use a piece of aluminum foil that's about 1 foot long. Tape one end of the foil to the tube. Wrap the foil all the way around the tube twice, then tape the loose edge of the foil closed. If you have extra foil at the top, just tuck it neatly inside the tube. .   Go outside on a sunny day. Close one eye and hold the tube up to your other eye. You want the inside of the tube to be as dark as possible-so cup your hands around the opening of the tube if you need to. Look around your yard through the tube. The lid makes a screen that shows you upside-down color pictures! Hold your hand below the tube and move it very slowly upward. Your hand is moving up, but you'll see its shadow move down the screen!   How does a hole in the bottom of a Pringles® can make a picture of the world? The hole doesn't make the picture. The image of the world is always there. All the hole does is make it possible for you to see it. Suppose you point your Pringles® Pinhole at a brightly lit bouquet of flowers. Light reflects off the red rose, the blue iris, the white daisy, and the green leaves. If you hold a piece of white paper near the bouquet, some of that reflected light will shine on the paper-but it won't look like anything. That's because light bouncing off the red rose ends up overlapping with light bouncing off the blue iris, the white daisy, and the green leaves. There are many images of the bouquet on the paper-but they overlap with one another, and the colors all blend together, making a jumble of light. The hole isolates a small part of the light, sorting a single image from the jumble. Only a few of the light rays reflecting off each point on the rose are traveling in a direction that will let them pass through the hole. The same is true for light bouncing off all the other flowers in the bouquet. On the other side of the hole, these light rays reveal an image of the bouquet.   You've made a camera! This kind of camera is called a camera obscura-which is Latin for "dark chamber." The first camera obscuras were small rooms that were completely dark except for a tiny hole in a wall that let in a dot of sunlight. People in the room saw an image of the trees and sky on the wall opposite the hole-and were amazed when the image disappeared at sunset! The Home Scientists in the Graff family improved their Pringles® Pinhole by using a foam soda can holder as an eyepiece. It made the inside of the tube dark, and was easier to use for people who wear glasses.