Laboratory Based Case Studies

1. Laboratory Based Case Studies Frank J. Dinan Dept. of Chemistry/Biochemistry Canisius College

3. 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 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 (<5 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..

4. A Teacher’s Tale • Frustration with expository (cookbook) labs • The “solution” • The response • Resignation

5. 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

6. Weaknesses of Expository Labs • “Cookbook” directions • No creativity or HOTS • Minimal learning • No reflection, synthesis or analysis • Reports forms to be “filled out”

7. Lab Based Case Studies Goals: *Increased student involvement, responsibility. *Student planning of work, evaluation of data, interpretation of results. *“Real-world” reports.

8. 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

9. Avogadro Goes to Court(WSJ) • Originally 2300 word case study • Professor’s challenge to class • Successfully student law suite • Remission of tuition, damages • Lab/class case--same challenge

10. 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

11. 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”

12. Analysis of a Murder Lab Case • 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

13. 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

14. 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.

15. A Metabolic Murder Mystery

16. 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

17. 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.

18. 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

19. Your Turn! • Develop lab based case • Good “hook” • Student directions • Learning goals • Narrative report