Experimental Design

Experimental Design

Pathophysiology

Scientific method: Scientific method is the tool that devised for the analysis and solution of problems in the natural world.

Stages of scientific method Observing a phenomenon that is in some way interesting or puzzling . Making a guess as to the phenomenon. Design an experiment in order to know the guess is true or false. Carry out experiment and on the basis of the results to decide the guess is true or false.

• Scientific experiments are popular in modern medical education. In conducting the experiment, the researcher must have an image of the specific content and object of the medical research. • This is called Experimental Design.

Control

features

randomization replication

∆ Experimental Design ( The basic forms) • • • • • • • • • •

1. Title 2. Introduction 3. Material and Method experimental object drugs and instruments dividing groups experimental steps 4. Experimental result( record or forecast) 5. Result analysis 6. Conclusion

1. Title Title should be suitable . • The title should be small , not big . • The title should be material( 具体的 ) ， not abstractive . Eg: The effect of A (some drug) to the cancer . The effect of A (some drug) to the lung cancer .

How to select the subject ? • Aim: What do you want to resolve? • Innovation: soul of the scientific research. • Advanced: • Scientific: • Feasibility:

The principle of select the subject : select the subject you are familiar and interested

2. Introduction (theory bases 、 research actuality 、 research aim) • Why do you choose this experiment? • What is the opinion of other researchers on this subject? and what did they have not resolved? • Bring forward your own hypothesis. hypothesis is the core of the experiment.

3. Material and Method • experimental object: The character of object must suit to experimental requirement and be economical .

• drugs and instruments: • dividing groups : Control、 Replication

• experimental steps:

Randomization 、

The sample content of experimental object  Quantitative target( 定量指标 ): ≥10 ( specific numerical value) For example: animal weight 、 blood pressure…

 Qualitative target ( 定性指标 ): ≥20 ( no specific numerical value) For example: good or bad 、 dead or alive…

Control is the first principle of experimental design ∗Eliminate the effect of non-experimental factors

Control group: Experimental group:

A+B+C+D A+B+C+D+E Result （ changes ）

Randomization is the second principle of experimental design .

• Random distribution is an important method to enhance the balance ( 均衡 性 )between the groups.

Replication is the third principle of experimental design

∗ Experiment be required certain replication. ( 实验要求一定有一定的可重复性 )

∗ Experiment be required certain replication times. ( 实验要求一定的重复次数 )

4. Experimental result ( record or forecast) • Record the original data and image. • Show the result by tables﹑ figures﹑ words et al.

For example:

Target

1

Target

2

Target

3

Target 4 Experimental group

Control group

C Experimental group

Control group

1

2

3

4

T

5. Result analysis • What did the changes of the experimental data or curve indicate? (disciplinarian) • Uphold or overthrow the hypothesis .

6. Conclusion • Analyse the experimental result and Summarize it in theory. • Conclusion should be felicitous( 恰当 ) and should not be exaggerated.

Thanks !