1. Austin Community College
Using a Classroom Response System to Implement an Interactive Lecture Demonstration
Paul Williams
Department of Physics
Austin Community College

2. Outline Classroom Response System (Clickers)
Classroom Response System (Clickers)
Class set funded by ACC Innovation Grant IG45
Interactive Lecture Demonstrations
Newton’s 3rd Law ILD with clickers
Assessment

3. Classroom Response System (Clickers)
Instructor Poses MC Question projected on screen
Students have input device which they use to answer question (IR or RF)
Instructor’s computer has receiver to detect student answers
Students answer anonymously and immediate feedback is given to students

4. Interactive Lecture Demonstrations
Developed by Sokoloff and Thornton
Present Demonstrations with a Learning Cycle
Good tool for promoting active engagement and for eliciting and confronting common non-Newtonian conceptions

5. ILD Process Demonstration is described
Demonstration is described
Students predict outcome on their own
Small group discussion occurs and then students predict outcome again
Predictions are obtained from students
Students record final prediction – Excellent application of Clickers
Demonstration is carried out
Students Describe the Results
Comparable physical situations are elicited from students

6. Sample ILD – Newton’s 3rd Law
Two force probes measure the forces between objects for eight different situations
In each situation students were asked to predict the relative magnitude and direction of the forces between the objects

7. Sample ILD Task
A massive cart, the truck, is pushed towards a light cart, the car, that initially isn’t moving. How does the force exerted by the truck on the car compare to the force exerted on the car by the truck.

8. How do the magnitudes of the forces compare? (BY)
The truck exerts a greater force than the car
The car exerts a greater force than the truck
The forces are equal
Cannot be determined 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

9. How do the directions of the forces compare? (BY)
How do the directions of the forces compare? (BY)
The directions are the same
The directions are opposite
Cannot be determined 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50

10. Assessment Details
Used Newton’s 3rd Law (N3L) ILD in lieu of lab activity on N3L in General Physics I
ILD was given after lecture on N3L
Post test consisting of 10 Questions on N3L taken from FMCE were given following all instruction on force
Also examined free response question on Newton’s 3rd Law on Unit test
Gave print version of ILD to section of Engineering Physics I
Looked at same 10 questions from FMCE pre/post

11. Results
N3L Subset of FMCE
GP1 Mean Correct 9.5
EP1 5.8 pre, 7.3 post

12. Unit Test Question: Ice Skater pushes on wall, identify force that accelerates the skater.
Identified Force
PHYS 1401
(N = 18)
PHYS 2425
(N = 13)
Reaction force to student pushing on wall 10 8
Student pushing on wall 5 2
Static Friction 3
Force between objects

13. Unit Test Question: Ice Skater pushes on wall, identify force that accelerates the skater.
Relationship between action/reaction pairs
PHYS 1401
(N = 18)
PHYS 2425
(N = 13)
Equal in magnitude/opposite in direction 13 10
Equal in magnitude 4 1
Reaction Force Greater 2

14. Unit Test Question: Ice Skater pushes on wall, identify force that accelerates the skater.
Free Body Diagram
PHYS 1401
(N = 18)
PHYS 2425
(N = 13)
Correct 9 10
Omitted Reaction Force 3
Put action/reaction pair on FBD 4 2
No vertical forces 1

15. FCI
Pre 10.5
Post 15.6
g = .30

16. Conclusions Results are promising but inadequate statistics
Results are promising but inadequate statistics
Will continue the experiment
Plan to do at least one more ILD with Clickers on Angular Momentum Conservation