11/26/2008
ConcepTests During Lectures
Craig Ogilvie, cogilvie@iastate.edu
„
„
„
Mini-lecture on a topic for 10 minutes
‰ Challenging
Ch ll
i multiple-choice
lti l h i question,
ti
examples
l ttoday
d
Two rounds per question
st
‰ 1 round, each student answers individually, commits
nd round, discuss in group, then recommit
‰ 2
Citations:
‰ Johnson,
Johnson Johnson
Johnson, and Smith (1991)
(1991), Cooperative Learning:
Increasing College Faculty Instructional Productivity.
‰ Mazur E. (1997), Peer instruction: a user’s manual.
20 Feb 2007
Craig Ogilvie
1
Advantages of Class-Discussions
„
„
Commit, then discussion => all participate
‰ Brings ideas out into open
‰ Learn, often by just explaining
‰ Students receive feedback on their understanding
‰ Energizes classes, allows students to catchup
Prof immediately knows level of understanding
20 Feb 2007
Craig Ogilvie
2
1
11/26/2008
Motion in 1-Dimension
„
„
Force in one direction changes velocity in that direction
E.g. drop rock from top of cliff, gravity accelerates downwards
‰ rock’s downward velocity increases, rock accelerates
Larger velocity =>
Increase in distance traveled in a time period
20 Feb 2007
Craig Ogilvie
3
Motion in 2-Dimensions
„
„
Velocity in one direction unaffected by force in another direction
Throw a rock horizontally off a cliff
‰ Vertical velocity increases due to gravity
gravity, rock accelerates
‰ Horizontal velocity unchanged during fall
During two identical time intervals
rock moves same distance horizontally
and further vertically
=> trajectory is a parabola
20 Feb 2007
Craig Ogilvie
4
2
11/26/2008
Question: Trajectory of Drifting Shuttle, 1st round
Space shuttle is drifting in the y-direction. Captain fires the
side-boosters. so that the shuttle accelerates in the x-direction.
Which is the correct trajectory of the shuttle?
Constant v
1.
y1
y
accelerate
x
2.
y
x
2
x
3.
y
3
x
0 of 338
Craig Ogilvie
20 Feb 2007
5
Question: Trajectory of Drifting Shuttle, 2nd round
Space shuttle is drifting in the y-direction. Captain fires the
side-boosters. so that the shuttle accelerates in the x-direction.
Which is the correct trajectory of the shuttle?
Constant v
1.
y1
y
accelerate
x
2.
y
x
2
x
3.
y
For each time interval,
shuttle moves same distance y
larger distances in x.
3
x
0 of 338
0%
1
20 Feb 2007
Craig Ogilvie
0%
0%
2
3
6
3
11/26/2008
Improvement During 2nd Round
Red: swivel seats
Blue: regular theater
p
To be published
Journal College
Science Teaching
Metastudy: Using concepTests compared to lectures
=> improved understanding of core concepts
R. Hake Am. J. Phys. 66, 64- 74 (1998).
20 Feb 2007
Craig Ogilvie
7
Mechanics of Two Rounds
„
„
Posted on “tips” web-site
‰ Create 2nd round slide with solution, graph, answer etc.
‰ Insert duplicate slide using Powerpoint toolbar
‰ Delete, solution, graph, answer from 1st round slide
‰ Rearrange slides
‰ Use TP’s comparative link under “tools”
Approximately 10% of the time, software freezes during a round
‰ Bug?
‰ Stop slide show, reset current slide, continue
20 Feb 2007
Craig Ogilvie
8
4
11/26/2008
Summary
„
„
Use challenging conceptual questions that pushes
students to apply the topic of the mini-lecture
‰ Two rounds,
rounds individual commits,
commits discuss,
discuss commit
Have used broad range of questions
‰ Problem-solving
¾ What would you do next?
¾ What strategic mistake did the student make?
‰ Prediction
¾ Start of material, instead of after mini-lecture
¾ What will happen in a demo?
20 Feb 2007
Craig Ogilvie
9
5