1. -any unauthorized reproduction is strictly prohibited
The Scientific Method
A Mr. K Presentation
-any unauthorized reproduction is strictly prohibited

2. Science starts with a … Research question
What the scientists wants to know

3. There are two general types of research:
Experimental
Descriptive

4. Descriptive research is…
Based mainly on observations

5. Examples include Making models Dissections
Observing animals in the wild

6. Example… How do the survivors of a tornado react to the disaster?
No variables; data is based on watching and talking to survivors

7. Experimental research is…
The manipulation and control of variables

8. Speaking of variables….

9. What are the three types of variables?
Independent variables
Dependent variables
Controlled variables
Also called constants

10. 1. Independent variables are…
What is being tested
What is being changed
The difference between the groups
The ‘cause’ of a change

11. 2. Dependent variables are…
What is observed
What is measured
The data
The ‘effect’ caused by the independent variable

12. 3. Controlled variables are…
Things that could change, but don’t
Kept constant by the scientist
Allow for a fair test

13. So an experimental question has to indicate the variables
How the independent variable will AFFECT the dependent variable
What the EFFECT of the independent variable will be on the dependent variable

14. For example…
How does the temperature of ocean water affect the speed of a hurricane?
Independent variable
T of ocean water
Dependent variable
Speed of a hurricane

15. Predictions
Educated guesses about what will happen during an investigation
Based on prior knowledge (observations, background research, etc)

16. For example…
People in disasters will react by trying to help others as much as possible.
This is a PREDICTION because it’s a guess about what you think will happen.

17. Hypothesis (plural – hypotheses)
Special kind of prediction
What makes it so special???
It’s a guess about the VARIABLES & their relationship, in particular,
How will the independent variable affect the dependent variable?????????

18. How to write a hypothesis
Use an If, Then statement
IF the independent variable changes, THEN the dependent variable changes
This type of sentence shows what the IV will do to the DV

19. For example…
IF the T of ocean water increases, THEN the speed of a hurricane will increase.
This shows the expected relationship between the independent variable (the T of ocean water) and the dependent variable (the speed of a hurricane)
If the T of ocean water changes, it will cause the speed of a hurricane to change too.

20. Planning the investigation – Experimental Design
You absolutely, positively have to know what the variables are!
What you are changing
How you are changing
What you are measuring
How you are measuring
Repeated trials
Data tables

21. Data tables?
Numerical (quantitative) data organized in rows and columns
The specific independent variables are listed
The number of trials are listed
Blanks are left for the data (dependent variable) to be filled in

22. Title Describing the Data
Trial
Variable 1
Variable 2
Variable 3 1 2 3 4 5
Average

23. Analyzing the data Reduce the data
Do something to make the amount of data smaller
Central tendencies
Mean (average)
Median
Mode
Range
frequency

24. Analyzing the data Graph the data
Lets us see trends, patterns, relationships, comparisons
Bar graphs
Let us compare data
Line graphs
Lets us see trends or changes

25. This shows a comparison of types and amount of trash on a beach.
Bar graph
This shows a comparison of types and amount of trash on a beach.

26. Line graph
This shows how the grade point average has been changing over several years. The trend is an increase in GPA.

27. Conclusions How we sum up the investigation
Does the data support the hypothesis?
If it does – we accept the hypothesis
If it does not – we reject the hypothesis
All back up what you say with data
Evidence

28. Communicate what you know
Finding out something new doesn’t do anyone any good unless the new knowledge is shared
Journals & magazines
Presentations