Scientific Method

1. Scientific Method

2. Natural Philosophy • Socrates, Plato, Aristotle • Were the “authorities” in Western thought from about 500 BCE to 1600 AD • Believed that there was a perfect world, but this world isn’t it

3. Natural Philosophy • Aristotle’s “perfect world” was accessible only through thought and contemplation. • Observation or experiment on this dirty, nasty imperfect world was useless in understanding “timeless truth.”

4. Beginnings of Science • Science, as we know it, evolved from “natural philosophy” (literally “thinking about nature”) starting about the year 1600 due to the work of Galileo, Bacon, and many others.

5. Scientific Progress • In the last 400 years, scientists have made incredible strides in their efforts to understand our universe (although there is still much to know). • Scientific progress has brought about technological progress that Galileo could not have imagined.

6. Scientific Methods • “The success of science has more to do with an attitude common to scientists than with a particular method. This attitude is one of inquiry, experimentation, and humility before the facts.” • Ideas Worth Sharing

7. Science Terminology • We need a common science vocabulary in order to communicate effectively with one another. • Keep in mind that the scientific meaning of a word is often different than its everyday meaning.

8. Steps in the Scientific Method • Question/Problem • Observation/Inference • Hypothesis • Experimental Design • Methods • Procedure • Results • Data Collection • Data Analysis • Conclusion • Further Research • Retest etc.

9. Observation • An observation is something you notice. • May be casual or even accidental • May be formal - experimental data are observations. • You make an observation based on your senses- sight, sound, hearing, taste etc. • Not all observations are correct - people make mistakes.

10. You Try Observing…

11. You Try Observing… • Where there any cars on the side of the street? • What color is the pick up truck driving in the road? • Were there any mini vans around? • What does the blue sign say? • What is the speed limit? • Are there any pedestrians on the road?

12. You Try Observing… • Answers: • Yes • Blue • Yes • Yard Sale • 35 mph • No

13. Scientific Inference • Logical interpretation based upon prior knowledge and experiences • Based upon observations • Example: On the first day of school when you entered the room, you most likely inferred that the individual in the front of the room was the teacher.

14. Problem/Question • A problem/question is formed based on observations and inferences • Must be testable • Can ask what, why, how • Example: Why is the sky blue? • How do trees grow so big? • What happens when…..

15. Hypotheses • A hypothesis is a possible explanation as to why something happens. • Most likely written in the If….then.. Because… form • A scientific hypothesis must be testable by observation - there must be observations that we can make to tell whether the hypothesis is correct or not. • If (we perform this experiment), then (this is what is going to happen), because (we found this out based on our research.)

16. Experimental Design • A set of materials needed to conduct the experiment • A detailed list of steps used to test the hypothesis.

17. Scientific Experiments Follow Rules: Variables • An experimenter changes one factor (independent variable) andobserves or measures what happens (dependent variable) .

18. The Control Variable/Group • The experimenter makes a special effort to keep other factors constant so that they will not effect the outcome. • Those factors are called control variables. • Controls are NOT being tested • Controls are used for COMPARISON

19. Other Variables • The factor that is changed is known as the independent variable. • The factor that is measured or observed is called the dependent variable.

20. One more thing… it is best to make several trials with each independent variable.

21. Data • Results of the experiment • May be quantitative (numbers) or qualitative(based on descriptions) • If numbers are used, they must be measured using the metric system!

22. Conclusions • A conclusion is a decision based on observations, facts, and experimental data. • It explains what happened and provides an explanation as to why it may have happened.

23. Further Research • Future Research must be addressed. • Describes possible experiments that could be completed in the future based on your conclusions.

24. Scientific Laws • A scientific law is a powerful summary of many facts. • Laws describe what happens, they don’t generally explain why they happen. • Laws can often be expressed very conveniently and concisely in mathematical form.

25. Scientific Theories • As experimental evidence (observations) accumulates, we can become more confident that a hypothesis is true. • A theory is a synthesis (powerful combination) of well-tested hypotheses. • Scientific theories tend to explain why scientific laws operate the way they do - theories are often called “models”. • Fun Fact: The word “theory” is probably the most misused science term - certainly by laymen, but even by scientists!

26. The Process of Science • In science NOTHING (well, hardly anything) is ever “proven once and for all”. • This process of testing facts, conclusions, laws, and theories with experimental observations NEVER ENDS.

27. Steps in the Lab Report • Abstract • Summary of the experiment • Background Information • Mention previous studies • Major findings of research • Question/Problem • Based on observation • Experimental Design • Materials/procedures • Data • Data Analysis • Discussion • Further Research • Works Cited

28. The End