1. Scientific methods are used to study living things

2. Two Basic Methods
Controlled Investigation
Field Study

3. Controlled Investigation
Usually done in the lab
Has only 1 manipulated variable
Scientist tries to keep all things the same EXCEPT the manipulated variable

4. Example of a Controlled Investigation
How does amount of water affect growth of sunflower plants over a 3 month period?
Manipulated Variable: Amount of water
Responding Variable: Growth of sunflower plant
Controlled Variables: size of pot, type of soil, amount of light, type of plant

5. Field Study Can be done in the lab or out of the lab
Scientist aims to test how a manipulated variable affects a responding variable OR aims to understand why a phenomena is occurring
Not all variables can be controlled

6. Example of a Field Study
How does type and amount of vegetation affect reproductive rates of desert tortoises?
Manipulated: type AND amount of vegetation
Responding: Number of eggs per spring
Controlled: Type of tortoise
CAN NOT CONTROL: Temperature, Rainfall, Soil type, Location, Elevation,
Land disturbance

7. Sometimes data collected indicates a problem
Example: Marbled Murrelet (a bird) populations are declining in California. Example: Desert Tortoise populations are declining

8. Biologists will often try to figure out how to fix a problem
This is done using the Scientific Design Process

9. Scientific Design Process
Identify a problem
Gather information about the problem (this can include data already collected)
Explore Ideas to solve problem
Choose a plan to solve problem
Write steps to do plan including a way to measure it’s effectiveness
Make a diagram of the plan

10. Example of Scientific Design Process
Problem: Marbled Murrelet populations are falling
Gather information about the problem: Ask a scientist: Where do they live? Where do they eat? What do they eat? Observe murrelets for a month and record what their predators are.
Explore Ideas to solve problem: plant more trees for nests, make more parks, educate public about predators so predator populations will decline
Choose a plan to solve problem: Educate public about predators so that we can keep predators away from Murrelets so that Murrelet population will increase
Make a diagram of your design solution: NEXT SLIDE!
Write steps to do plan: NEXT SLIDE!
Scientifically test solution: NEXT SLIDE!

11. Steps to do the plan Create signs about predators of Murrelets
Make sure signs tell visitors that birds attracted to picnics and trash (ravens, crows, jays) prey on Murrelet eggs
Post signs in areas where Murrelets have their nests
Diagram
Test Solution
Count and record the number of predators in nesting area before and after education plan to measure effectiveness of plan