Volume 6, No. 1, Winter 2002
Cover | Oslet | Perspective | Handhelds | Probeware | Monday's Lesson | Online Courses | e-Learning | Modeling
Probeware Takes a Seat in the Classroom
Educational Impact of Probes Improves with Time and Innovation
by Stephen Bannasch and Robert Tinker
For many years we have been developing probeware—probes, sensors, interfaces, supporting software, and related curricula for classroom lab activities. However, we have never seen anything like the burst of creativity that is currently driving innovation in this area. Eventually, these new developments will drive down the costs, increase the usability, and greatly improve the educational impact of probeware.
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Over the last year the Concord Consortium has developed an open source application called CCProbe that is scriptable, configurable, and supports probe- based visualization, analysis, and calibration components. CCProbe also includes components for folders, text, drawings, and images, which all can be integrated with the probeware to create curricular activities, and a lab book portfolio in which work can be saved and shared.
Although probeware has been around for a long time and its educational value is well documented, it is not widely used by teachers. We have identified several barriers to its broader adoption that our current work addresses:
Cost of computers
Many schools feel they can't afford the computers necessary for an entire class to use probeware. CCProbe will run on almost any handheld or desktop computer. Schools can take advantage of the inexpensive handheld computers or use their older desktop computers, and the hardware uses a serial port that is a standard part of most computers.
Cost of probeware
Previously, the major cost in equipping a lab with probeware was the cost of the probes, which can run $100 or more each, but our new interface box can use probes that are inexpensive to manufacture. Students can even make their own probes for the cost of parts ranging from 50 cents to five dollars each. Furthermore, the software is available free in our Open Source Library of Educational Tools (OSLET).
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The learning curve
Another perceived barrier is that probe software is so complex that it is difficult to master for both teachers and students. Investigations with CCProbe can be designed like Web pages in order to contextualize and simplify use of the tools. We have worked hard to make the software intuitive and easy to learn, with on-screen help and guidance. In addition, we are developing online short courses for teachers on the use of the materials.
Integration
Although some teachers feel it is difficult to integrate probeware into their teaching, we are creating standards-based science activities using probes that are easily modified by teachers on a desktop computer. These activities appear on desktop or handheld computers. Initially, we will support teacher review of student work on the desktop versions of CCProbe. Later the desktop software will be integrated with Pedagogica, which can provide scaffolding, guidance, and more embedded assessment.
Assessing student work
While it once was difficult to record and assess student work with probeware, CCProbe supports the CCLabBook system which allows all student work to be saved, reviewed, and commented on by the teacher.
By addressing these barriers, we have created affordable probeware with unprecedented flexibility, portability, and educational value.
The Software
CCProbe is an elegant and powerful probeware application that can be used by students to heighten their understanding of the world around them by combining measurement with the computer's ability to display, record, and communicate visualizations of the measured data.
Learning, however, requires more than a good tool. Students need to be guided,
challenged to predict, and encouraged to reflect. CCProbe uses the organizing
principle of a lab notebook, which contains both curricular activities and a
portfolio of student work. While CCProbe includes many traditional probeware
tools such as real-time graphing, analysis, calibration, and saved datasets, it
also includes software objects for taking notes, drawing sketches, answering
questions, and displaying images. Additionally, CCProbe supports folders and
compound objects similar to Web pages in which the basic objects can be combined
together into activities.
This functionality that CCProbe is built upon is what we call the CCLabBook system. All the activities and student work are saved in one place. At present we create activities using a structured XML-based editing system from which CCLabBook objects, HTML Web pages, and printed PDF versions of the activities are automatically generated. Soon, teachers will be able to easily modify the activities or create their own using a Web-based authoring system. Once generated, an activity can be distributed to all students. An individual CCLabBook can be easily moved between handheld and full-size computer systems allowing students to investigate, edit, and organize information anywhere.
After a class of students has completed an activity the work collected in individual CCLabBooks is combined on the teacher's computer where it can be browsed, critiqued, and archived. Additionally, the teacher can place new activities in the student CCLabBooks.
Runs On Most Computers
CCProbe and the CCLabBook system are written in Waba (an open source variant of Java) and run on a wide range of operating systems including PalmOS, WinCE, PocketPC, Windows, MacOS Classic, MacOS X, Linux and other Unix operating systems. This means that our software runs on almost any computer made in the last five years. As new computers are created, the software will quickly run on those, as well. No longer will our software become hostage to a machine that is discontinued, as happened with the Apple Newton and e-Mate. Another advantage is that teachers who learn to use our software on one computer can easily transfer their knowledge to any computer their school chooses to supply.
An essential design goal of the CCLabBook system is to support transparent communication of portfolio objects between all these systems. For example, after using CCProbe on a Palm computer to collect temperature and light data in the field, the LabBook on the Palm can be saved onto a server where it is accessible from other locations such as computers in the computer lab.
Beyond communication we are working on consolidation of student work for review and assessment. As the CCLabBook architecture and capabilities grow we are calling this expanded system CCFolio. Work is progressing on integrating the CCFolio system with Pedagogica.
| CCForceProbe |
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| CCLightProbe |
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| CCVoltageCurrentProbe |
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| CCTemperatureProbe |
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| CCSmartWheel |
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The Interface
The interface is the box that goes between the computer and probes (see schematic on page 8). Our latest design, called the CCProbeInterface, is built with the latest low-power, low-cost, precision electronic components. Its design reduces the cost of probes that are used with it. The interface has batteries to allow use of power-hungry probes as well as portable unattended datalogging operation. However, if the batteries are dead or missing, it can still communicate with the CCProbe software and inform the user.
The CCProbeInterface contains two kinds of voltage sensors. One is fast and moderately sensitive, while the other is extremely sensitive but slow. The fast one can sense two inputs, to within five millivolts, ten thousand times per second. This is good for detecting sound, the forces in a collision, or the flash from a bulb as it burns out.
The slow voltage sensor can detect four inputs to within a microvolt, about three times a second. This high sensitivity is valuable because we can dispense with the cost of electronics often used in input circuits. For instance, we can make a highly sensitive temperature sensor from two wires of different metals, a so-called thermocouple. The junction of a typical thermocouple generates a few tens of microvolts for every degree temperature change. This means that two wires can be made into a very sensitive thermometer, a sensor anyone can build.
Probes
As illustrated to the right, we have developed some exciting new probes, which are described in more detail on our CCProbeware Web site. Each of these probes has a memory chip that holds identifying and calibration information about the probe.
CCSmartWheel We have improved on the ultrasonic motion detector that we developed 16 years ago. The new probe is less expensive and easier for beginners to understand. It uses an optical encoder on a CD-ROM wheel. This wheel can be easily attached to a cart, meter stick, or pulley, making it quite versatile for measuring speed.
CCForceProbe We dusted off the old idea of using a Hall effect sensor next to a magnet on a metal arm—all quite inexpensive. When the sensor is midway between the poles of the magnet and one-half pole separation away, it is linear in displacement parallel to the probes. Since the displacement of the arm holding the magnet is proportional to force, this makes a very sensitive probe.
CCTemperatureProbe This probe uses the tiny tip of a thermocouple to measure temperature. It can be used for many experiments that were impractical when using an ordinary temperature probe. This sensor responds so quickly to changes in air temperature that the vertical temperature profile in a room can be determined in one 30-second experiment.
CCVoltageCurrentProbe This probe can be used to measure voltage or current. Further processing of these values in the CCProbe application allows the recording of electrical power and energy.
CCLightProbe This measures visible light levels in either an indoor or outdoor illumination range.
Availability
As mentioned earlier, CCProbe is free software that can be downloaded from the OSLET Web site, copied, and used as you wish. At this writing, CCProbe hardware is not yet commercially available. We are working with several vendors who have shown a strong interest in manufacturing the interface and probes at a reasonable cost. Check our Web site for the latest information on availability of the interface and compatibility with other interfaces.
At this stage, these innovations should be of immediate interest to researchers, publishers, hardware vendors, and programmers. It would be easy to support more interfaces or dataloggers in the software. We think this should make CCProbe very appealing to manufacturers of probeware or dataloggers who are interested in supporting their hardware with free software that runs on almost any computer.
CCProbe and the CCLabBook system should also be valuable to other educational researchers who could use a portfolio software system that also has probeware capabilities. For a small investment, new capabilities can be added, which can be both used and distributed by the research project and contributed back to the CCProbe community. If you need to add some functionality, but don't have access to programmers who can achieve this, please contact us.
We have a few prototype hardware sets consisting of a CCProbeInterface and the five standard probes available at $750 each. This is much higher than their eventual cost to users, because they were produced in a small quantity pilot production run. We would be delighted to make these available to anyone interested in extending our work, undertaking related educational research, or developing compatible products.
We hope that, in time, the CCProbe set of tools will become so inexpensive that any student can have access to them. As more teachers develop their own curricular activities using probeware, these devices will become familiar learning tools in every science classroom.
Stephen Bannasch (stephen@concord.org) and Robert Tinker (bob@concord.org) have been working together on probeware and related curricula for the past twenty-five years, the last eight of which have been at the Concord Consortium where Stephen is director of technology and Bob is president.
The projects described in this newsletter are supported by grants from the National Science Foundation, the U.S. Department of Education, the Noyce Foundation and others. All opinions, findings, and recommendations expressed herein are those of the authors and do not necessarily reflect the views of the funding agencies. Mention of trade names, commercial products or organizations does not imply endorsement.
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