Conceptual Understanding
versus
Algorithmic Learning
Margaret Asirvatham and Thomas Pentecost
Chemistry & Biochemistry
TIGER Presentation
January 24, 2008
Chemical Education Research
• Many novice learners tend to apply
algorithms without significant conceptual
understanding that must be developed for
students to be successful problem-solvers.
• Chemistry problems are challenging as they
may be expressed in different ways symbolically, at the particulate
(atomic/molecular) level, or at the
macroscopic level.
Limiting Reactant: Lecture Demo
Interactive Engagement
Mg(s) + 2 HCl(aq)  MgCl2(aq) + H2(g)
Flask #
Moles of Mg(s)
Moles of HCl(aq)
Flask 1
0.0125
0.1000
Flask 2
0.0250
0.1000
Flask 3
0.0500
0.1000
Flask 4
0.1000
0.1000
What will be the relative sizes of balloons above the flasks when the
reaction is complete?
100%
A) V1 = V2 = V3 = V4
80%
B) V1 < V2 < V3 < V4
60%
C) V1 < V2 < V3 = V4
40%
D) V1 < V2 = V3 < V4
20%
E) V1 < V2 = V3 = V4
0%
A
B
C
D
E
Colors represent three different lecture sections taught by the same instructor.
Limiting Reactant: Atomic/Molecular View
The diagram represents a mixture of S atoms and O2 molecules in a closed
container.
O2 molecule
S atom
Which diagram shows the results after the mixture reacts as completely as
possible according to the balanced equation:
2S + 3O2  2SO3
(a)
(b)
(c)
(d)
(e)
Only 15% of the students (Spring 2006) selected the correct answer (d) after a whole semester of Gen
Chem 1!
Fall 2006 (Pre) 10.5% correct; (Post) 41.8%
http://jchemed.chem.wisc.edu
Can our students interpret
atomic/molecular view
representations?
H2O(s)  H2O(l)
2H2O(l)  2H2(g) + O2(g)
Acknowledgment: Silberberg’s “Chemistry: The Molecular Nature of Matter and Change”
General Chemistry Concepts
Exam 1 Question, Fall 2006
Examine the molecular views presented below:
I
II
III
IV
Which of these represents a pure compound?
A) I (601)
B) II (11)
C) III (1)
D) IV (179)
General Chemistry Concepts
Final Exam Question, Fall 2006
Which of these atomic/molecular views represent pure substances?
I
II
III
IV
A)
I and III (1)
B)
II and IV (55)
C)
I, II and IV (616)
D)
II, III, and IV (7)
General Chemistry Concepts
Exam 1 Question, Fall 2006
Consider the molecular views of reactants as they are converted to products in the
boxes shown below:
nitrogen
oxygen
chlorine
Which of these best represents the balanced equation for this reaction?
A) NO + Cl2  Cl2NO (69)
B) 2NO + Cl2  2ClNO (677)
C) N2 + O2 + Cl2  2ClNO (3)
D) NO + Cl  ClNO (43)
General Chemistry Concepts
Exam 1 Question, Fall 2006
Examine the molecular view of the chemical reaction between AB and B2 in the gas
phase:
Select the correct statement about this reaction.
A) The balanced equation for the reaction is AB + B2  AB3. (23)
B) AB and B2 are present in stoichiometric amounts at the start of the reaction. (131)
C) AB is the limiting reactant. (615)
D) The product of the reaction is A2B. (23)
Meta-communication
“The most powerful tool for changing students’
attitudes about learning and enlisting them as
active collaborators in their own education is
meta-communication  high level
communication about the nature and purpose
of the “normal communication” within the
course.”
I.Beatty, “Transforming Student Learning with
Classroom Communication Systems,” EduCause
Research Bulletin, Volume 2004, Issue 3, February
2003, p. 11.
Meta-communication
“Meta-communication can and should address
the learning objectives of the course and its
components, the virtues of instructional
techniques and styles employed, and the
reasons why particular assignments are given.
Experience shows that students are far more
cooperative when they understand why they
are being asked to do something.”
I.Beatty, “Transforming Student Learning with
Classroom Communication Systems,” EduCause
Research Bulletin, Volume 2004, Issue 3, February
2003, p. 11.
Cubic Unit Cells
Acknowledgment: Silberberg’s “Chemistry: The Molecular Nature of Matter and Change”
Solid State: Cubic Systems
Using New Lecture Demo Models
Consider an atom in the simple cubic crystal lattice. What is the
maximum number of unit cells that share this atom in the threedimensional structure?
Num ber of Unit Cells that share a Corner Atom in the Sim ple Cubic Crystal Lattice
Num ber of unit cells that share a corner atom in the sim ple cubic crystal lattice
40
100
35
30
Percent Responses
Percent Responses
A) 2
B) 4
C) 6
D) 8
E) 12
120
45
25
20
15
80
Series1
60
Series2
Series3
40
10
20
5
0
A
B
C
D
0
A
Before
B
C
After
D
E
Cubic Unit Cells
Simple Cubic Crystal Lattice
Lessons Learned
• Atomic/molecular visualization skills must
be developed and reinforced
• Formative assessment with clickers and
peer collaboration in large lecture classes
• Conceptual questions must be developed to
address higher-order thinking skills as well
as common misconceptions
• Integration of real-world context and
effective lecture demonstrations are
essential
Solutions
Chemistry Concept Challenges
F06/Sp07
• Series of assignments developed to:
• Think in terms of “atoms and molecules” (and ions)
• Make connections among macroscopic observations, symbolic
representations, and what’s happening on the particulate level
• Use, interpret, produce, and translate among various representations
in chemistry (words, symbols, particulate-level representations,
mathematical relationships, graphs)
• Articulate their understanding
• Relate chemistry to the “real world”
• Make connections among several chemistry concepts
Examples:
• Representations of Matter
• Reactions in Solutions
• Gases
Recitation Workshops F07/Sp08
• Background
– CHEM 1111 & 1131 5 credits
• 3 hrs/week lecture
• 4 hrs/week recitation/lab
• Incorporate CCCQ materials into recitation sessions.
– Allows materials to be used in a group work environment.
– Allows us to follow physics workshop model.
– Removes grading burden from TAs.
Recitation Materials
• Merged CCCQ materials with existing
materials (algorithmic problems)
• Some CCCQ materials became pre or post
laboratory questions.
• Some new materials written.
Ex: Thermochemistry
Implementation
• To implement this model for recitation needed
to train TAs to facilitate.
• Before fall semester 2007 - three day training
for new graduate students that were likely to
teach CHEM 1111 that term.
TA Training
• Three days (Wed - Fri)
• ~ 1.5 days on Chemical Education Research
and justification for recitation model.
• ~1.5 days on content - modeling recitation
sessions with 6 of the content units.
Support
• At weekly TA meetings suggestions for use of
the materials were presented.
• Areas of potential student confusion were
pointed out.
Evaluation
• Observations of Recitation sessions were done,
limited.
• Students were interviewed about aspects of the
course.
• TA feedback in the form of written comments
at various times during semester.
• Results of Concept Survey.
Results to Date
• Seeing some movement in the desired
direction.
• TA training was successful!
– Faculty comments
– TA feedback
Thanks!