Laboratory Based Case Studies

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Laboratory Based Case Studies

• Frank J. Dinan
• Dept. of Chemistry/Biochemistry
• Canisius College

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(No Transcript)
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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 (lt 1
  centimeter) the bottom center of the heating well
  (DO NOT USE A MERCURY THERMOMETER). Secure the
  thermometer to the ring stand with a one-hole
  rubber stopper and a three-pronged clamp.
  Connect the Thermowell heater to a (disconnected)
  Powermate heat controller, or its equivalent.
  After assuring that the Powermate control is in
  the OFF mode, connect it to an electrical outlet.
  Place it on a low setting (setting 2 for Model
  3A). The sand at the bottom of the well should
  reach 100 deg. C within 20 minutes. If this does
  not occur, increase the dial setting by one unit
  and wait for 5 minutes for continued heating,
  then note the temperature. If the temperature
  has not yet reached 100 deg. C, repeat the
  process until the temperature remains a little
  (lt5 deg.) above 100 deg.. The thermometer may
  then be removed. Record the Powermate setting in
  the indicated spot on page 2 of the data sheet
  provided for this experiment.
• Etc, etc.,etc..

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A Teachers Tale

• Frustration with expository (cookbook) labs
• The solution
• The response
• Resignation

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Strengths of Expository Labs

• Topic well defined
• Explicit instructions
• Goal known in advance
• Teaches technique
• Minimal investment in equipment, personnel
• Simultaneous instruction of large numbers

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Weaknesses of Expository Labs

• Cookbook directions
• No creativity or HOTS
• Minimal learning
• No reflection, synthesis or analysis
• Reports forms to be filled out

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Lab Based Case Studies Goals

• Increased student involvement,
  responsibility.
• Student planning of work, evaluation of
  data, interpretation of results.
• Real-world reports.

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Characteristics of Lab Based Cases

• A Good Hook
• Challenging problem, experimental solution
• Minimal, but appropriate, faculty guidance
  provided
• Consideration of student safety
• Requires real-world, narrative report
• Examples follow

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Avogadro Goes to Court(WSJ)

• Originally 2300 word case study
• Professors challenge to class
• Successfully student law suite
• Remission of tuition, damages
• Lab/class case--same challenge

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Avogadro Goes to Court, But You Can Save Him

• 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

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Analysis of a Murder Lab Case(NPR)

• Boys headless, limbless, nude torso floating in
  Thames
• Ritual sacrifice
• Identification seemingly impossible
• Professors 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

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Analysis of a Murder Lab Case

• Students given summary of case
• Act to assist Scotland Yard
• Given victims bone sample for analysis
• Given samples from different regions of Nigeria
• Student experimental data indicates location of
  victims Nigerian home
• Students act as detectives, plan apprehension of
  killer
• Report of case written to Chief Inspector
• Published in Journal of Chem. Education, 2007

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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

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FDA Inspired Lab Case

• 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.

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A Metabolic Murder Mystery
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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

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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
• Students skills improve sharply with practice,
  instruction
• Poor quality reports returned for re-writing.

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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

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Your Turn!

• Develop lab based case
• Good hook
• Student directions
• Learning goals
• Narrative report