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Learn about Interactive Lecture Demonstrations (ILDs) at the U of M - how they engage students, improve understanding, and the mechanics ILD sequences. Discover the benefits, challenges, modifications, and future possibilities of ILDs.
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Interactive Lecture Demonstrations at the U of M Brian Andersson University of Minnesota Based on Interactive Lecture Demonstrations developed by David Sokoloff and Ronald Thornton
Traditional Demo Sequence • Instructor introduces demo (prop or mechanical device) during a discussion of related material. • Instructor may solicit informal predictions from class, but not always. • The demo is performed. • Instructor briefly explains what the demo displayed and a brief discussion may occur. • Students usually have little part in process.
Current State of Demos • Some demos give confusing or unconvincing results. • Current list of demos contains very few computer aided activities. • A way of including the students in the demonstrations is needed.
What is an Interactive Lecture Demonstration? • The demonstration is presented in such a way that the students become involved. Passive environment becomes active. • Demonstrations are performed using computers. The data collected is presented to the students. • Predictions and results are discussed amongst students and entire class. • The ILDs are not intended to replace the traditional lecture, but to enhance it.
Mechanics ILD Sequences • Mechanics 1: Human Motion • Mechanics 2: Motion with Carts • Newton’s 1st and 2nd Laws • Newton’s 3rd Law • Energy of a Cart on Ramp Each sequence (containing 4-7 demos) is designed to be completed in approximately 40 minutes.
Complete Interactive Lecture Demonstration Procedure • Perform the demo without MBL measurements. • Ask students to record individual predictions. • Have class engage in small group discussions with nearest neighbors. • Students record final prediction. This is turned in. Predictions may be graded as a form of attendance points.
Procedure Continued • Ask for representative predictions from students. • Perform demo with MBL data displayed. • Ask a few students to describe the results of the demonstration. Students write down results on a sheet they keep. • Discuss different physical situation based on same concept.
Critical Steps for Instructor • Instructor must convince the students that the probes used are collecting real and accurate data. • Instructor must pay attention to class during step 3. Know when to move on to next step. • Instructor must have an agenda during steps 7 and 8. He/she may need to direct discussion toward important points.
Is the Complete Procedure Feasible at the U of M? • Will professors want to spend up to 40 minutes on an ILD? • Can this procedure be modified to decrease the lecture time used while maintaining the benefits?
Modifications to Procedure • Use an ‘Ask the Audience’ type of device to solicit predictions from class. Bar graphs of the results could then be displayed, ala Who Wants to be a Millionaire. • Perform only 1-2 demos instead of the 4-7 in each sequence.
Who Has Used The Program? • To date Eric Ganz, Paul Ellis, Tonnis Ter Veldhuis, and Gloria Martinez have performed portions of at least one sequence. • Professor Ganz has been my main guinea pig by performing portions of sequences 2, 3, 4, and 5. • All have felt the program work well (for the most part) and that it helped students understand the concepts a little more.
Difficulties Observed During Initial Trials of Software • Acceleration vs. time can be noisy. • Maximum kinetic energy is consistently lower than maximum potential energy in energy demo. • Total energy sometimes parabolic, not constant.
Sample ILDs • Program called LoggerPRO used for data acquisition. • 1st demonstration: Energy of a Cart • Cart moves up and down an incline • KE, PE, and ME vs. time are plotted • 2nd demonstration: Newton’s 3rd • Two force probes are hooked together • The force acting on each is displayed
Demos Beyond Mechanics Sequence • More demos have been developed with the help of Prof. Ganz. • These demos illustrate static vs. sliding friction, Hooke’s Law, motion of a spring, and motion of a pendulum.
Possible Future of ILDs at the U • Incorporate E&M ILDs involving voltage probes, Hall probes, etc. • Use Physlets with a modified ILD procedure. • Use LabVIEW programs from labs to either introduce upcoming problems or reinforce lab work.
Do Students Learn From ILDs? • Studies were conducted at the University of Oregon and Tufts University. • Average understanding after traditional instruction in dynamics rose to less than 20%. • Average understanding after inclusion of ILDs was greater than 70%, rising as high as 90%. D. Sokoloff and R. Thornton, “Using Interactive Lecture Demonstrations to Create and active Learning Environment,” The Physics Teacher35, 340-347 (Sep. 1997)