Making Laboratories Count
Better Integration of Laboratories in
Physics Courses
by
Jim Sizemore, Ph.D.
Physics and Engineering Professor
Tyler Junior College, Tyler, TX
Greg Sherman, Ph.D.; Mike Broyles, Ed.D.
Physics Professors
Collin College, Plano, TX
Acknowledgements:
Meade Brooks, Ashok Kumar, Paul Johnson
Outline of Talk
• Issues
– Students don’t take labs seriously
– Poor math preparation
• Solution
– Prelab packets
– Quiz on prelab
– Objective grading of labs
• Preliminary Results and Conclusions
Students don’t take labs seriously
• Informal survey of students
– Admitted not preparing
– Admitted expectation of good grade with only
modest effort
Poor Math Preparation
• Course has Pre-Calculus Prerequisite
• Gave Pre-Calculus Quiz at Start of Semester
1) What is the equation of the line that includes the points (9.1,9.5) and (-7.8,-4.8)
2) Solve for x: -0.54x2 + 13.53x – 25.53 = 0
3) Refer to the following figure. What is sin(), cos(), tan(), , and h?

h
2.65
I
4) Solve for and calculate I: db =10log 10
where db = 27 and Io = 10-12 W/cm2.
Io
• Surprised by inability to answer questions
– Didn’t expect result, thus did not keep records
1.07
Prelab Packets
• Separated Lab into PreLab and Lab
Components
• Students were required to turn in Prelab at
beginning of lab
• Example on next slide
Example Prelab
Pre-Lab Quiz
• Give Quiz at Beginning of Lab over Content of
Pre-Lab
– Insures students do pre-lab preparation
– Insures on-time attendance
• Quiz Asked Open Ended Questions. Examples:
1) The quantity mv is referred to as momentum and is conserved. In other words, when you add up the
momentum of all the particles vector-wise before collision it equals the sum (vector-wise) of the
momentums of all particles after collision. There is only one particle before collision with the pendulum
– the steel ball. What is the expression for its momentum?
2) After it collides with the ballistic pendulum the two particles together have a momentum. What it the
expression to the combined momentum of both after collision?
– Grading Quizzes was Time Consuming
– In Future Will Change to Multiple Choice Quizzes
Objective Grading
• Labs Often Taught by Inexperienced
Instructors
• Tendency to Judge Based on Scale of 1 to 10
• Solution: Precise Point Assignment on 0 to
100 Scale
– Example from Previous Slide
Example Prelab
SOLVE Method
• 5 Steps
1) Sketch or Study
2) Organize knowns and
unknowns
3) Line up (equations)
4) Vary (get working
equation)
5) Evaluate
• Award 20% Credit for
Each Step Completed
• Per Arnold Arons –
systematic approach is
important
Application of Bloom’s Taxonomy to
Quantitative Fields
• Get Away From Memorizing Equations
• Bloom’s Taxonomy Simplified
– Know
– Understand
– Apply
– Synthesize
– Critique
• Award 20% for each step of Bloom’s Taxonomy
Completed
Other Grading Criteria
• Tables and Graphs
– 20% for accurate tabulation or graphing
– 10% for equations
– and labeling axes, showing units, etc.
• Dimensional Analysis
• Using Unit Fractions when Converting Units
• 3 Sig. Figs or Better
• Etc. – at
http://www.funphysicist.net/physics_1401/labs/list.htm
Results
• Some Evidence of Improvement Through
Semester
• Overall Course Grade
Grade (student estimate & actual)
12
estimated
10
8
6
4
2
0
A
B
C
D
F
actual
Results – Study Outside Class
• Evidence of Greater Effort
Outside Study
7
6
5
4
3
2
1
0
A
B
C
A >3 hr, B ~3 hr, C ~2 hr, D ~1hr, F <1 hr
D
F
Results – Lab Grades
• Maybe Improvement Through Semester
• However Inconclusive
Lab Grade (percent vs. week)
120
Pre-Lab Grade (points vs. week)
120
100
100
80
80
60
60
40
40
20
20
0
0
1
2
3
4
5
6
7
8
9
10
11
12
13
1
2
3
4
5
Lab Quiz Grade (points vs. week)
12
10
8
6
4
2
0
1
2
3
4
5
6
7
8
9
10
11
12
6
7
8
9
10
11
12
Conclusions
• Evidence of Better Student Engagement and
Effort
– Increased effort is appropriate
– Underprepared students spend more time, however
succeed
• Grades Improve
• Doesn’t Require New Labs or Rewrites
– Develop grading scheme, break out pre-labs, develop
multiple choice pre-lab quizzes
• Results Not Unequivocal, but are Encouraging
Future Work
• Gather Statistics Over Several Semesters to
Understand Variability due to Differences
Between Labs
• Retain Baseline Information of Beginning of
Semester Quiz to Compare to Mid-Semester
and End-of-Semester Data
• Establish Control Group for Comparison