Transcript Laboratory Based Case Studies

Laboratory Based Case Studies
Frank J. Dinan
Dept. of Chemistry/Biochemistry
Canisius College
Cookbook-101
• Re-crystallization Experiment
• Set up a sand bath assembly as follows:
Requisition a Thermowell heater, support plate
and digital thermometer. Attach the support plate
to a ring stand. Fill the cavity of the Thermowell
heater with sand to within one centimeter of the
top and set it on the support plate. Adjust the
apparatus to a convenient height. Position the
digital thermometer so that the tip of the probe
almost touches (< 1 centimeter) the bottom center
A Teacher’s Tale
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Frustration with expository (cookbook) labs
The “solution”
The response
Resignation
Strengths of Expository Labs
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Topic well defined
Explicit instructions
Goal known in advance
Teaches technique
Minimal investment in equipment,
personnel
• Simultaneous instruction of large numbers
Weaknesses of Expository Labs
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“Cookbook” directions
No creativity or HOTS
Minimal learning
No reflection, synthesis or analysis
Reports forms to be “filled out”
Lab Based Case Studies Goals:
*Increased student involvement,
responsibility.
*Student planning of work, evaluation of
data, interpretation of results.
*“Real-world” reports.
Characteristics of Lab Based
Cases
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***A Good Hook***
Challenging problem, experimental solution
Minimal, but appropriate, faculty guidance
provided
Consideration of student safety
Requires “real-world”, narrative report
Examples follow
Avogadro Goes to Court
(WSJ)
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Originally 2300 word case study
Professor’s challenge to class
Successfully student law suite
Remission of tuition, damages
Lab/class case--same challenge
Avogadro Goes to Court, But You
Can Save Him
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Shortened (~2300 to ~350 words)
Briefly outlined
Challenged to save Avogadro
Students plan experimental approach
Equipment, material available on request
Experiments carried out, calculations done
Narrative report to law firm of Dewey Cheatem &
Howe
Analysis of a Murder Lab Case
(NPR)
• Boy’s headless, limbless, nude torso floating in
Thames
• Ritual sacrifice
• Identification seemingly impossible
• Professor’s research on Sr distribution
• Bone Sr content indicated Nigerian origin
• Analysis narrowed origin to 500 sq. mi. region
• Clever detective work led to apprehension of
”persons of interest”
Analysis of a Murder Lab Case
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Students given summary of case
Act to “assist” Scotland Yard
Given victim’s “bone sample” for analysis
Given samples “from different regions of Nigeria”
Student experimental data indicates location of
victim’s Nigerian home
• Students act as detectives, plan apprehension of
killer
• Report of case written to “Chief Inspector”
• Published in Journal of Chem. Education, 2007
Two Versions of Murder Case
• Versions for advanced and intro. courses
• Advanced version: students analyze “bone
samples” for their Sr concentration
• Intro. level version: students interpret Sr
concentration data sets
• In both, data evaluated, conclusions drawn,
plan formulated, report written
FDA Inspired Lab Case
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Juicing the juice complaint (FDA)
Fresh vs. reconstituted orange juice
Fluoride ion concentration key difference
Fluoride ion selective electrode
Students approach based on F ion
concentration in two juice types.
A Metabolic Murder Mystery
A Metabolic Murder Mystery
Same Case, Two Labortory Experiments
• Patricia Stallings murder accusation
• Conviction, reversal, release, apology
• Students placed in role of lab personnel
• Results “determine guilt or innocence”
• Must avoid errors of hospital laboratory
• Gas chromatography, general chemistry
• PCR, biochemistry laboratory
Why Narrative Reports?
• Lab reports often form(s)
• Unlike “real-world” reports
• Science students writing skills often inferior to
liberal arts students
• Lack of practice, experience
• Student’s skills improve sharply with practice,
instruction
• Poor quality reports returned for re-writing.
Additional Lab Based Case
Studies
• Accidental Drowning or Foul Play by Monica
Konaklieva, American Univ.
• Filthy Lucre by Ed Acheson, Millen Univ.
• Dem Bones: Forensic Reconstruction by Alease
Bruce, U. Of Mass. At Lowell
• Shark Attack! by Herbert House, Elon University
• The Zoom Lens: A Case study in Optics by Alan
Cheville, Oklahoma State University
Your Turn!
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Develop lab based case
Good “hook”
Student directions
Learning goals
Narrative report