Using a Classroom Response System to Implement an Interactive Lecture Demonstration

Paul Williams

Department of Physics

Austin Community College

pwill@austincc.edu

Outline

Classroom Response System (Clickers) Class set funded by ACC Innovation Grant IG45

Interactive Lecture Demonstrations Newton’s 3rd 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 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

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 2 3 4

0% 0%0%0%

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

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

How do the directions of the forces compare? (BY)

1 2 3

0% 0%0%

1. The directions are the same

2. The directions are opposite

3. 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

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

Results N3L Subset of FMCE

GP1 Mean Correct 9.5 EP1 5.8 pre, 7.3 post

FMCE N3L Subset

02468

10121416

1 2 3 4 5 6 7 8 9 10

Number Correct

Fre

qu

ency EP1 Pre

EP1 Post

GP1 Post

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 3

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 1 2

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 1

FCI Pre 10.5 Post 15.6 g = .30 PHYS 1401 FCI

0

1

2

3

4

5

6

1 3 5 7 9 11 13 15 17 19 21 23 25 27 29

Number Correct

Fre

qu

ency

PRE

POST

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