A description of the Authorware programming language and PULP technical background is included in this chapter. Finally, as a conclusion to this chapter, a discussion of student use of the program and the research methods used during the research process is given.
The use of computers in physics education
Each program is structured in a game and a tutorial that allows the student to adjust the different parameters such as thickness and position of the lens. Mechanics is a branch of physics that deals with the study of the effect of forces and energy on a system.
DESIGN STRATEGIES FOR A RESEARCH- BASED INSTRUCTIONAL COMPUTER PROGRAM
Ove rview
Rigorous testing of the program is unconditional, as it determines the effectiveness of the program. This gives the interviewer an indication of the level of understanding the student has prior to using the program.
Discussion of the Authorware programming lang uage which is the basis of Pulp
A smaller screen size was used so that the program's processing speed did not decrease and the program's initial animation sequence ran smoothly. A useful introduction to Authorware's capabilities is a set of tutorials that provide hands-on instruction on the program's dynamics.
Discussion of the volunteer PULP groups
Of the 139 NON-PULP students surveyed, 84 had written upper level mathematics and 55 had written at the standard level. The average percentage of the entire sample of NON-PUL P students in the standard grade in mathematics is a higher "D" symbol (between 55 and 65%).
INVESTIGATION OF STUDENTS ' UND ERSTANDING OF THE USE OF BASIC MEASURING INSTRUMENTS
Introduction
Readings are taken by noting the position of the reading line on the drum scale. In the case of the Vernier Calipers and Traveling Microscope section of the program, each object box is randomly generated (Figure 3.4).
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Assessment of stu dents' interaction with Basic Measuring Instruments
By having an assessment carried out immediately after the two PULP sessions, an indication of the effectiveness of the program was given. To counteract reading from the edge instead of from zero on the vernier scale slider, the program was modified to include an arrow, as shown in Figure 3.6.
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CLICK ANYWHERE TO REPEAT QUESTION
This section of the program was generally well received by students as it served as a refresher course on the use of the measuring instruments. The program has been adapted to include clear indications of the correct point from which the readings should be taken and this is reflected in the results (Graph 3.2). Measurements taken from the micrometer screw gauge are particularly difficult as students must be aware of the readings from three scales, the drum, main and subscales.
The analysis of the evaluation of the micrometer thread gauge shows that the students progressed in all areas relevant to the performance of measurements with this instrument (Graph 3.3).
PULP ASSESSMENT OF THE SIMULATION OF REFRACTION OF LIGHT THROUGH A TRIANGULAR PRISM
Introduction
The concept of minimum deviation of light passing through a triangular pnsm IS introduced at the freshman level in formal lectures and in the laboratory. A discussion of the minimum deviation of light passing through a triangular prism is provided, illustrating the concept of symmetry, which includes the mathematical consequence of symmetry (i.e. eI = e4 and e3 = e2). The angle of deviation for each triangular prism is measured between the undiffracted light beam and the refracted light beam.
Examples of light entering the triangular prism at different angles are given in the Worked Examples section, which illustrates how the angles of incidence, refraction, and exit are formed and measured (Figure 4.3).
Points were awarded for correctly calculating the angle of refraction at the first boundary and for correctly determining the refractive index of the prism. This leads to the determination of the refractive index and the angle of refraction of the prism. Despite recognizing the refractive index and angle of incidence at the first interface, many students took 82 for the angle of incidence (84) at the second interface.
Most students used Snell's law to determine the interior angles of the prism and defined these angles as 82 as the angle of incidence at the first interface and 83 as the angle of emergence at the second interface.
Snell's Law
The angle of refraction of a prism, although not a new concept to the students, also caused much confusion. To establish the correct usage and definition of these terms, two separate pages were included in the program's background information (Figures 4.6 and 4.7). It was decided not to include these hints in the main body of the optics section, as these may be overlooked by students.
The first page (Figure 4.6) deals with Snell's law and in the first instance shows light moving from air to perspex.
Refracting Angle
Summary of Minimum Deviation
The ability to correctly reproduce an equation, such as the equation that defines Snell's Law, should not be an indication that the student understands the theory related to that equation. Basic understanding of concepts such as medium, interface, and symmetry is overlooked because of the confidence students place in their ability to define equations mathematically. By showing students a visual and mathematical representation of symmetry in terms of the triangular prism, the program has changed this belief.
For students to succeed in more advanced questions in optics, a solid grounding in the basics is required.
RESEARCH CONDUCTED ON THE EFFECTIVENESS OF A THEORY- BASED TO OL FOR INVESTIGATING STUDENT UNDE RSTANDIN G
OF ELECTRICITY
Introduction
34;flat" and needs to be replaced, many students reason that current is consumed in the circuit (Duit & von Rhoneck). Consider, for example, parallel branches connected directly across the terminals of a battery and parallel branches connected elsewhere in the circuit. But for parallel branches connected elsewhere in the circuit, a change in one branch affects the other branch.
Students who consider circuits in isolation claim that in the second circuit described above, a change in one branch has no effect on the second branch.
Electrostatics is the branch of electricity that deals with charges at rest. Experiment shows that charged objects
Select one of the heading belows to learn more about Electrostatics
Force
Coulombs Law
Electric Field at a Point X
- Electric Field due to a Point Charge Q 5. Neutral Point
- Potential Difference 7. Electron Volt
Definitions can be accessed via the navigation icons at the bottom of the displayed screen. To address these difficulties, the examples in the Electrostatics Worked Examples section (Figure 5.3) are based on typical exam questions and show the student the context in which the concepts are tested and applied. The method used in these examples illustrates how a question can be broken down into components to solve it.
It shows the student that in order to answer the question, it may be necessary to find intermediate results first.
First assessment of students after interaction - Electrostatics
Coulomb's law states that the magnitude of the electric force acting between two stationary charges is directly proportional to the magnitude of each charge and inversely proportional to the square of the distance between them. However, of the students who used the correct equation in defining Coulomb's law, the majority (94%) based their explanation solely on the mathematical operations performed on each variable. 34;It is the product of 2 charges that are distant from each other, which is inversely proportional to the square of the distance between them.
Students also leave out the fact that it is the magnitude of each charge and the magnitude of the force that is determined by Coulomb's Law.
Second assessment of students after interaction - Electrostatics
Summary of Electrosta tics
Although much research on electrical learning has focused on students' understanding of electrical circuits containing resistors, little has addressed the problems associated with circuits containing capacitors. In a capacitor circuit, the calculation of the reciprocal equivalent capacitance for series-connected capacitors is determined by the sum of the reciprocal values of each of the capacitors, while the equivalent capacitance for parallel capacitors is determined by the sum of the individual capacitors. In a series resistive circuit, the equivalent resistance is calculated by finding the sum of the individual resistances, while in a parallel circuit, the reciprocal of the equivalent resistance is equal to the sum of the reciprocals of the individual resistances.
CAPACITORS IN PARALLEL
CAPACITORS IN SERIES
First assessment of students after interaction - Capacitors
By drawing the capacitors from top to bottom in the plane of the page, the question tests the students' ability to recognize a series and parallel connection and to then calculate the equivalent capacitance in the circuit. They then used the reciprocal of this result and added it to the reciprocal of the third capacitor to find the equivalent capacitance. A further observation from the analysis showed that in calculating equivalent capacitance for capacitors in series, students often set the sum of the reciprocal capacitors equal to the equivalent capacitance instead of the reciprocal of the equivalent capacitance.
The results of the second evaluation show significant gains in both groups by improving the calculations in resolving parallel capacitors into a single capacitor and the equivalent capacitance of the entire circuit.
RESISTORS IN SERIES
RESISTORS IN PARALLEL
This leads to an equation that shows students why the total resistance in a series circuit is the sum of the individual resistances. 3• If all resistors have the same ohmic value, then the value of the current flowing through each resistor is the same (ie i1= iz= i3). The sum of all the currents (i" from and i), whether passing through the same resistors or not, is equal to the total current in the circuit.
Using Ohm's law and a constant potential difference in the circuit and across the resistors leads to a reciprocal equivalent resistance equal to the sum of the reciprocal values of the individual resistors.
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- Second assessment of students after interaction - Resistors
- Summary of Resistors
- CONCLUSION
- Pamphlet used III PULP campaign to recru it first yea r physics students into programme
- First test based on Basic Measuring Instruments . The images below show the vernier calipers, micrometer and tr aveling
- First assessment based on the Minimum Deviation section of PULP
- First asse ssment the Electrostatics section of PULP
An analysis of the question was based on correctly calculating the equivalent resistance for resistors in series and then using this result to determine the total resistance in the circuit. Points were also awarded for calculating the total power consumed in the circuit. There was a common error in the method used among the 9% of students who incorrectly calculated the equivalent resistance of the circuit.
Previous research done in these content areas served as the foundation of the program and was incorporated into the design structure.
PHYSICS UNDERGRADUATE LEARNING PROGRAM
First assessment of students' under standing of capacitors using the Cap acitors sect ion of the program
First assessment of student understanding based on the Resistors section of the program
PHYSICS UNDE RGRA DUATE LEARNING PROGRA M
Second assessment of resistors, capacitors and electrostatics given by independent source and used to determine whether PULP had any
Sample code of Basic Measuring Instr uments
BIBLIOGRAPHY
The development of first-year physics students' ideas about measurements in terms of point and set paradigms. Investigating whether using the computer as a tutor can improve 1st year Pen Tech science students' conceptual understanding of electrical concepts. Preliminary studies on students' understanding of electricity and magnetism for the development of a model-based diagnostic tool.
