Some examples of scientific experiment design.

1. The Design of
Experiment: Examples
Yiming Chen, Oct. 22, 2010

2. Design of Experiment
Phenomena Hypothesis
Experiment
Theory

3. Examples
• Detonation Test, in World War II
• Controlled Experimentation on Scurvy

4. Detonation Test
in WW II
1. E.B. Wilson, The analysis of experimental data,
An Introduction to Scientific Research, McGraw-
Hill, New York (1952)
2. http://en.wikipedia.org/wiki/Explosive_material

5. Detonation Test
• Factors of Explosion
• Chemical composition;
• Initiator;
• Shape of explosive shell;
• Material of explosive shell;
• ………………

6. Detonation Test
Too Complicated to study!

7. Detonation Test
Cylinder Expansion Test: An Simplified Model
• Standard amount of explosive is loaded
into a long hollow cylinder;
• Detonated at one end;
• Data is collected concerning the rate of
radial expansion of the cylinder wall;

8. Cylinder Expansion Test

9. Simplified Ideal Model
• Simplification: Remove variables by ideal Model;
• Standardization: Comparative and Repeatable;

10. Simplified Ideal Model
Powerful tool to study fundamental mechanism in detail.

11. Experiment on
Scurvy
1. http://en.wikipedia.org/wiki/
Design_of_experiments
2. http://en.wikipedia.org/wiki/Scurvy
3. James Lind (1716-94) of Edinburgh and the
treatment of scurvy, Arch Dis Child Fetal
Neonatal Ed 1997;76:F64-F65

12. Experiment on Scurvy
• Scurvy was at one time common among
sailors due to lacking of fresh vegetables &
fruits;
• Described by Hippocrates (460 BC–380
BC), and partially cured by herbal in many
native cultures;
• Killing large numbers of the passengers and
crew on long-distance voyages.

13. Experiment on Scurvy
• James Lind carried out a controlled
experiment to develop a cure for scurvy.
- 12 men selected, all suffering from scurvy;
- Divided into six pairs, giving different
additions to their basic diet for a period
of two weeks;

14. Experiment on Scurvy

15. Experiment on Scurvy
Pair Additional Food
1 A quart of cider
2 Drops of Sulfuric Acid
3 1.5 pint of seawater
4 Garlic, mustard, horseradish
5 Spoons of Vinegar
6 Oranges and Lemons

16. Experiment on Scurvy
Pair Additional Food
1 A quart of cider
2 Drops of Sulfuric Acid
3 1.5 pint of seawater
4 Garlic, mustard, horseradish
5 Spoons of Vinegar
6 Oranges and Lemons

17. Experiment on Scurvy
Pair Additional Food
1 A quart of cider
2 Drops of Sulfuric Acid
3 1.5 pint of seawater
4 Garlic, mustard, horseradish
5 Spoons of Vinegar
6 Oranges and Lemons

18. Experiment on Scurvy
Pair Additional Food
1 A quart of cider
2 Drops of Sulfuric Acid
3 1.5 pint of seawater
4 Garlic, mustard, horseradish
5 Spoons of Vinegar
6 Oranges and Lemons

19. Experiment on Scurvy
Pair Additional Food
1 A quart of cider
2 Drops of Sulfuric Acid
3 1.5 pint of seawater
4 Garlic, mustard, horseradish
5 Spoons of Vinegar
6 Oranges and Lemons

20. Experiment on Scurvy
Pair Additional Food
1 A quart of cider
2 Drops of Sulfuric Acid
3 1.5 pint of seawater
4 Garlic, mustard, horseradish
5 Spoons of Vinegar
6 Oranges and Lemons

21. Experiment on Scurvy
Pair Additional Food
1 A quart of cider
2 Drops of Sulfuric Acid
3 1.5 pint of seawater
4 Garlic, mustard, horseradish
5 Spoons of Vinegar
6 Oranges and Lemons

22. Experiment on Scurvy
Pair Additional Food
1 A quart of cider No comparable improvement
2 Drops of Sulfuric Acid No comparable improvement
3 1.5 pint of seawater No comparable improvement
4 Garlic, mustard, horseradish No comparable improvement
5 Spoons of Vinegar No comparable improvement
6 Oranges and Lemons Recovered within week

23. Scurvy Experiment
• Conclusion: Scurvy could be cured by Citrus
fruits;
• Mechanism: resulting from a deficiency of
vitamin C, which is required for the synthesis
of collagen in humans.

24. Scurvy Experiment
But ......

25. Scurvy Experiment
• He fed patients with H SO , seawater: lacking
2 4
of proper knowledge;
• Additional foods are pre-assigned to patients:
missing randomized allocation of subjects to
treatments.

26. Controlled
Experimentation
• Compare experimental sample against
controlled sample;
• Controlled sample is identical to
experimental sample except the variable
need to be tested (independent variable);

27. Don’t Leave
It'll be more appealing later!