Student Misconceptions
about Science
RFUMS Master Teachers’ Guild
John Becker, Ph.D.
Learning Objectives
Participants will:
• Learn how to identify misconceptions that students
hold
• Identify the likely sources of the misconceptions
• Learn what remedies can correct misconceptions
Misconceptions about Learning
From Faculty Focus, January 29, 2014:
1. Learning is fast
2. Knowledge is composed of isolated facts
3. Being good at a subject is a matter of inborn
talent rather than hard work
4. I’m really good at multi-tasking, especially
during class or studying.
SCIENCE MISCONCEPTIONS
• Flawed mental models, not just missing facts.
– Sun revolves around the earth?
• One definition (Michael, 1998):
– An incorrect model for a phenomenon regardless
of its possible origin.
• Published examples from: physics, chemistry,
neuroscience, psychology, biochemistry,
exercise science, heart failure, etc.
Some hot (and cold)
misconceptions from physics
1. Everything contracts in the cold
– Fill a water glass and put it in your freezer
2. Everything expands in the heat
– Plate-with-a-hole problem
Plate-with-a-hole problem
• Put a metal plate with a hole in
the center into an oven and heat it.
• What happens to the hole?
• Take 1-2 minutes by yourself
A
B
C
You are not alone
• Eric Mazur thoroughly covered heat in
Harvard’s freshman Physics lecture course.
• But, many students got it wrong, as did
Harvard professors, as did physiologists at a
meeting.
Group Activity
Discuss among yourselves for 3-4 minutes
– And, imagine metal molecules as people standing
in a circle, who want to get as far away from
neighbors as possible.
Group Activity, cont.
C
How to find misconceptions
• Multiple choice exams (over several years)
– PrepU exam bank has “misconception alerts”
– Formative pre-tests (Lazarowitz, 2005)
• Office visits/tutor sessions
• Ask for reasons during lecture (Socratic)
– Direct interlocution or indirect with clickers
• Educational literature in your profession
Sources of misconceptions
• Learned in other courses (K-16)
• Grounded: not from other education
– Intuitive ideas from everyday life
– Even observing their own body does not help
dissuade them
• Teleology: “the body needs to…”
Sources that we can control
• Sometimes it is language:
•
•
•
•
•
Absorption ≠ Reabsorption ≠ Resorption
Two renal thresholds (Cheng, 2012)
Missing adjective: arterial blood pressure
“Elastic” in physics vs everyday language
“positive feedback” in physiology vs pop psychology
• Sometimes it is poor analogies
– Arterial vs venous compliance
• In the future, Virtual Reality programs may
apply reductionism to complex biological
problems (Richardson, 2011)
Compliance
• From physiology textbooks: venous compliance is
20X that of arterial compliance.
• Compliance = Δvolume/Δ pressure
– (how easy it is to fill an elastic container)
• Dr. Becker’s bad 2-D analogy: thin and thick
rubber bands
– But venous grafts to replace blocked coronary arteries
must be tough.
– A better 2-D analogy: area within a circle vs. area
within an ellipse.
Shapes
Normal vein
Vein when blood is stored
in an organ (e.g., depend
your hand)
• The “fabric” of arteries and veins are similar, but circles have
bigger areas than ellipses of the same circumferences
• And in 3-D, cylindrical cans hold more volume than oval cans
• Compliance = Δvolume/Δ pressure
– (how easy it is to fill an elastic container)
Sometimes it is figures or charts
• The terminology of the basic physiological
concept of “homeostasis” is not used
consistently across textbooks (and sometimes
within one textbook), especially in figures
(Michael, 2013)
– e.g. see-saw in a feedback loop drawing may lead
students to misconceive that homeostasis only
operates when there is an imbalance
Homeostasis Drawing
Control
Center
Receptor/
Sensor
Effector
Variable in homeostasis
• Does the
system shut
down when
there is
balance?
• Where is the
“set point”?
• “Negative
feedback” is
not explicit
Based on Michael 2013
Sometimes it is graphs
• Some textbooks use graphs from experiments,
but students may think the graph explains an
observation of an unprovoked situation.
Stroke Volume in Experiments & Exercise
Silverthorn
Physiological Examples
• Cardiac Output = Heart Rate X Stroke Volume
– H.R. goes up in exercise, but what about stroke volume?
– Many students think it goes down or stays the same
– Analysis from research (Michael, 1998): “Cardiac output
must be kept constant”
– Does this come from emphasis on feedback loops?
• But the variable held constant is blood pressure, not cardiac
output.
– Does this come from the previous figure?
• Others: right & left cardiac output; pulse vs blood
velocities; resistances in parallel (Palizvan, 2013)
Respiratory
• Minute Ventilation = Resp. Rate X Tidal Volume
– R.R. goes up in exercise, but what about VT?
– Similar misconception: VT either stays the same or
drops to keep ventilation per minute constant
– Or, not enough time to fill the lungs at high rates
– In this case, students ignore what they can observe
after running up the stairs (deeper & faster
breathing)
What to do?
• Re-lecturing does not work:
– Misconceptions persist across tests and across
courses (Michael, 1998; Silverthorn, 2002)
– Eric Mazur abandoned lecturing
Remedies
• Sometimes labs or demonstrations can help, esp.
if students are asked to predict
• Sometimes making students aware that this
concept is often misconceived:
– Teach to misconceptions “targeted instruction”
(Christensen, 2008)
– Let your tutors know, too
• Explain the components & limitations of
analogies (Broom 2010)
• “Interventions” (Leinonen, 2013)
• Hints & Peer Interaction (e.g. discussion among peers about
the hole problem)
• Other Active Teaching methods
– Caveat: some students don’t want active methods
Informal Survey at RFUMS
Dr. Oblinger: Hair & fingernails grow after death.
• The skin dries and shrinks away from the
bases of hairs and nails, giving the appearance
of growth.
DISCUSSION
1. Share your pet misconception.
2. Ideas about remedies?
3. Does it matter?