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

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

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

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

ILD Process 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

Sample ILD – Newton’s 3 rd 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

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.

How do the magnitudes of the forces compare? (BY) 1. The truck exerts a greater force than the car 2. The car exerts a greater force than the truck 3. The forces are equal 4. Cannot be determined

How do the directions of the forces compare? (BY) 1. The directions are the same 2. The directions are opposite 3. Cannot be determined

Assessment Details Used Newton’s 3 rd 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 3 rd Law on Unit test Gave print version of ILD to section of Engineering Physics I Looked at same 10 questions from FMCE pre/post

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

Unit Test Question: Ice Skater pushes on wall, identify force that accelerates the skater. Identified ForcePHYS 1401 (N = 18) PHYS 2425 (N = 13) Reaction force to student pushing on wall 108 Student pushing on wall52 Static Friction3 Force between objects3

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 1310 Equal in magnitude41 Reaction Force Greater12

Unit Test Question: Ice Skater pushes on wall, identify force that accelerates the skater. Free Body DiagramPHYS 1401 (N = 18) PHYS 2425 (N = 13) Correct910 Omitted Reaction Force3 Put action/reaction pair on FBD 42 No vertical forces11

FCI Pre 10.5 Post 15.6 g =.30

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