1. The Scientific Method

2. What is Science?
Science--organized way of using evidence to learn about the natural world
Goals:
Investigate and understand natural world to explain events.
Use explanations to make useful predictions

3. Scientist Specialization
Biologists
Ecologists
Population biologists
Zoologists
Cellular biologists
Molecular biologists
Real Scientific Method Experiments of the Past

4. Scientific Method *OBSERVATION/QUESTION RESEARCH *HYPOTHESIS
*EXPERIMENT
*ANALYZE DATA/CONCLUSION

5. 1. Observations and Questions
Use your senses to gather information of your surroundings
Inferences are your logical interpretations of what you sense
Questions then arise…….
Ex: Observe/ask why plants near my neighbors yard grow bigger than the others in my yard.

6. Research Research question Any previous experiments done?
Prior knowledge?

7. 2. Hypothesis “If [I do this]……then [this will happen]”
Hypothesis-scientific and testable explanation/solution to problem
“If [I do this]……then [this will happen]”
Ex: If I put fertilizer on my plants, then
they will grow bigger

8. 3. Experimental Procedure
Controlled experiments- designed to test only one factor at a time
Split subjects you are testing into groups:
#1 Experimental Group-given the experimental factor or changed in some way
#2 Control Group:-NOT changed
Experimental Group
Fertilizer
Control Group
No Fertilizer

9. Variable-factor in experiment that is subject to change.
Independent variable- factor in experiment that you purposely manipulate Ex: fertilizer
Dependent variable- factor that you observe and that depends/changes in response to independent variable Ex: Plant height
Only test ONE independent variable while having many constants.

10. 3. Experimental Procedure
Constant variables
Other variables involved that stay the same for experimental and control group
Ex: Same amount of water, same sunlight exposure, same kind of plants..etc

11. Must be a controlled, reproducible procedure
Testing effects of
only ONE manipulated
Independent variable
Other scientists
need to be able to
reproduce it and
find same results.

12. 4. Results
Record data
Qualitative data -physical traits (qualities) that can be described
Ex: Blue flower petals
Quantitative data -measurements (quantities) that can be taken
Ex: Plant measures 92cm tall
Utilize pictures, tables, graphs
Trends noticed?

13. Qualitative? Quantitative?
Experimental Group Control Group
fertilizer no fertilizer

14. 5. Drawing Conclusions
Hypothesis is either supported or rejected. NEVER “PROVEN!”
If supported further testing
If rejected hypothesis changed and tested again
Can be partly true
Findings always useful!!!
Conclusion?

15. Findings always useful!
“I didn’t fail 1000 times, the light bulb was an invention with 1000 steps” –Thomas Edison

16. Overview State the Question or Problem Draw a Conclusion
Section 1-2
State the Question or Problem
Draw a Conclusion
Form a Hypothesis
Publish Results
Set Up a Controlled Experiment
Record Results

17. Scientific Theory
Theory-a well-supported explanation of some aspect of the natural world
It’s the closest you can get to scientific fact
It’s a hypothesis than has been tested and supported many times
Used to make future predictions
Not “a hunch” like it means in everyday language
If contradictory evidence found, theory revised
There is no evidence against them
A hypothesis is a POSSIBLE explanation, whereas a theory IS an explanation

18. Graphing Graphs are a useful tool in science.
The visual characteristics of a graph make trends in data easy to see.
One of the most valuable uses for graphs is to "predict" data that is not measured on the graph.

19. Graphing Steps Identify the Variables Determine the range
Determine the scale
Number and label each axis
Plot the points
Draw the graph
Give your graph a title

20. Identify the Variables
Independent Variable - (the thing you changed)
Goes on the X axis (horizontal)
Should be on the left side of a data table.
Dependent Variable - (changes with the independent variable)
Goes on the Y axis (vertical)
Should be on the right side of a data table.

21. Range Subtract the lowest data value from the highest data value.
Do each variable separately.

22. Scale
Determine a scale, (the numerical value for each square), that best fits the range of each variable.
Spread the graph to use MOST of the available space.

23. Label Axis's
You need to tell everyone reading your graph what the graph means.
Be sure to include units.

24. Plotting
Plot each data value on the graph with a dot. You can put the data number by the dot, if it does not clutter your graph.

25. Drawing Draw a curve or a line that best fits the data points.
Most graphs of experimental data are not drawn as "connect-the-dots".

26. Title Your title should clearly tell what the graph is about.
If your graph has more than one set of data, provide a "key" to identify the different lines
While your high school teachers might not like it, I do like putting your name in the title of the graph.
Rachel and Max’s Sunspot Graph

27. Interpolation
Interpolate: predicting data between two measured points on the graph.

28. Extrapolation
Extrapolate: extending the graph, along the same slope, above or below measured data.