1. The fundamental cornerstone of ALL SCIENCE
The Scientific Method
The fundamental cornerstone of ALL SCIENCE

3. Words we will understand by the end of today…
Observation (hey, I wonder….)
Inference (Educated guess based on experience)
Hypothesis…and the Null Hypothesis (must be testable)
Data – quantitative and qualitative
Variables (independent and dependent)
Controlled variables

4. Being Scientific…is there any such thing as scientific fact?
Divide the statements below into Opinions and Facts
What is the difference between an Opinion and a Fact?
If you have time, write down 4 things that you know as facts and 4 things you think are opinions.
1. Pineapple makes pizza taste better
2. On average, the Sun is 150 million miles from the earth
10mins
A theory has been extensively tested and is generally accepted as a fact, while a hypothesis is a speculative guess or opinion that has yet to be tested. One definition of a theory is to say it's an accepted hypothesis.
Here is a good animated explanation
3. Girls should be able to work in any field they choose
4. The blood tests show that the patient died of a bacterial infection

7. This process is called The Scientific Method
Scientists use observations to form hypotheses that can be tested by experiment to provide reliable theories that explain how the world works .
This process is called The Scientific Method
Observation
15mins. Student notes and 5 mins sorting exercise
The scientific method is used to convert a Hypothesis into a Scientific Theory which in time will be accepted as a Scientific Law
Ibn al-Haytham (Alhazen), 965–1039 Iraq. The Arab scholar considered to be the father of the modern scientific method

8. A Scientific questions is posted as a Hypothesis (or a Null hypothesis)
I wonder?…..
Based on our observations, we formulate a research question
Our research question is presented as a hypothesis, based on our scientific reasoning (inference)
We typically present the Null hypothesis

9. So why do all experiments require a hypothesis?
‘If then…’
We must have a principle that we can objectively test
The hypothesis is an educated guess (inference), based on your previous observations
The hypothesis MUST BE TESTABLE
We generally state the Null Hypothesis for cause-and-effect relationships

11. When designing an experiment, you must identify and define experimental VARIABLES

12. Experimental Variables
You must define 3 types of variable:
Independent Variable -What is manipulated
Dependent Variable –what is measured - the data collected during the investigation
Controlled Variable – a variable that is not changed…allow for a “fair test”

13. Graphing experimental VARIABLES
Independent – what I change (X- axis)
Dependent – what you measure (Y-Axis)
Controlled – what remains constant
(Uncontrolled – variables which may be hard to control)
Ideally you should have all variables controlled, excepting one dependent and one independent variable

14. When does a hypothesis become a theory?
When a hypothesis is repeatedly confirmed by experiment and observation (USING THE SCIENTIFIC METHOD), it may become generally considered as a THEORY
THEORIES are the most reliable, rigorous, and comprehensive form of scientific knowledge
Some well known scientific theories:
Cell theory
Evolutionary theory
Theory of relativity
Climate change theory

17. Designing a controlled experiment

18. Designing a controlled experiment
Formulate a focused research question and hypothesis
Identify ALL of the relevant variables (independent, dependent, controlled, uncontrolled)
Decide how to manipulate the independent variable – range
Decide how many repeats of the experiment you need to do
Decide if you are including a control group

19. How much data is enough?

20. Some practice examples…
For the following observations…
Write a research question
Write a hypothesis
Identify the variables… Independent Dependent Variables which should be controlled…

21. Observation: Students of different ages take differing times to complete a jigsaw puzzle…I can time this....

22. Observation
Research question
Hypothesis
Independent Variable
Dependent Variable
Controlled Variables

23. What was the independent variable?
Ages of the students
Different ages were tested by the scientist

24. What was the dependent variable?
The time it to put the puzzle together
The time was observed and measured by the scientist

25. What was a controlled variable?
Same puzzle
All of the participants were tested with the same puzzle.
It would not have been a fair test if some had an easy 30 piece puzzle and some had a harder 500 piece puzzle.

26. Another example:

27. I have just learned how to make an electromagnetic system out of a battery, some wire and a nail. The magnet I made can pick up paper clips. I have tested the system with different sizes of nail. Each different size of nail can pick up a different number of paper clips.

28. Observation
Research question
Hypothesis
Independent Variable
Dependent Variable
Controlled Variables

29. Independent variable:
Sizes of nails
These were changed by the scientist

30. Number of paper clips picked up
Dependent variable:
Number of paper clips picked up
The number of paper clips observed and counted (measured)

31. Controlled variables:
Battery, wire, type of nail
None of these items were changed

32. One more:

33. Observation: When I am making a boiled egg for breakfast and turn the hob on to its top setting, my egg boils more quickly.
I can measure the temperature of the water that I place the egg in.
I can start with warm or cold water

34. Observation
Research question
Hypothesis
Independent Variable
Dependent Variable
Controlled Variables

35. Independent variable – temperature of water
Dependent variable – time to cook an egg
Controlled variable – type of egg

36. The greater the amount of soap in a soap and water mixture, the bigger a soap bubble can be blown.
Design an investigation to test this hypothesis.
Identify the variables
What exactly will be changed? How will it be changed?
What exactly will be measured? How will it be measured?

37. The farther a ball drops, the higher it will bounce.
Design an investigation to test this hypothesis.
Identify the variables
What exactly will be changed? How will it be changed?
What exactly will be measured? How will it be measured?

38. Using the Scientific Method to explain an observation
The Scientific Method helps turn scientific ‘questions’ into scientific ‘facts’ (improved understanding of the world)
With your partner, apply the scientific method to test any one of the following observations: OQHPTAS
Rattle snakes seem to follow an invisible trail to their prey after it has been bitten
Aeroplanes with the biggest wings travel the furthest
Milk goes bad quickly if left in an open container
Meat turns into maggots if left in the open
15mins – 10mins to do, 5mins to share
Observation  My car doesn't start  Ask some questions like am I out of petrol?, did I leave the lights on? Does the engine sound funny? Is the voltage too low? Is this my car? To form a hypothesis (My car does not start because the battery is flat)  I predict that if I recharge my battery that my car will start  Test = recharging the battery  Analysis = to see if car starts after recharge  Scientific Law = a car can not start with a flat battery
Questions you might want to ask regarding the snake:
A rattlesnakes eyes are only sensitive to visible light
A pair of organs located under the eyes detect invisible light in the form of heat
A rattler’s tongue “smells” certain odors in the air
The sight or smell of an unbitten animal does not trigger the rattler’s tracking action

39. End http://www.youtube.com/watch?v=EYPapE-3FRw
For an amusing discussion on SM see Richard Feynman’s lecture