The Scientific MethodThe Scientific Method

Using Plant Experiments to discover the Scientific Method

Types of Plant ExperimentsTypes of Plant Experiments

• Plus or Minus Treatment– With or without

• Dose-Response Study– Variation in amount

• Factional Experiment– Two variables

• Comparative Experiment– Plant species vary

Using the Scientific Inquiry MethodUsing the Scientific Inquiry Method

• Plant a Question

• Sprout a Guess

• Design a Growing Experiment– Identify independent variable

– Identify dependent variable

• Record Fruitful Observations

• Harvest Conclusions

Using Experimental Design MethodsUsing Experimental Design Methods

• Brainstorming - Four Question Strategy

• Experimental Design Diagrams

• Determine Procedure

• Conduct Experiment

• Record Results

• Analysis of Results

• Conclusion

Four Question StrategyFour Question Strategy

1) What materials are readily available for conducting experiments on ?

2) How do act?

3) How can I change a set of _ materials to affect the action?

4) How can I measure how ______ respond to the change?

What materials are readily available for conducting experiments on PLANTS?

Plants

Soil

Fertilizers

Water

Light

Containers

How do PLANTS act?

Grow

Reproduce

Produce oxygen

Produce sugar

Produce fruit

How can I change a set of PLANT materials to affect the action?

Plants

Soil

Fertilizers

Water

Light

Containers

How can I measure how PLANTS respond to the change?

- Count the number of leaves

- Measure stem length

- Determine growth rate

- Count the number of flowers

- Mass of fruit produced

- Measure the diameter of the stems

- Measure chlorophyll absorption

Select VariablesSelect Variables

Independent Variable - change (#3)

- limit to one variable

- all other variables are constants

Dependent Variable - measure (#4)

- limit to one variable

Experimental Design DiagramExperimental Design DiagramTitle: The effect of (IV) on the (DV).

Hypothesis: If (IV), then the (DV), will . . .

Independent Variable:

Dependent Variable:

Constants:

Control Variation I Variation II Variation III

# of Trials # of Trials # of Trials # of Trials

Example IExample I

Title: The effect of the amount of fertilizer on

the height of bean plants.

Hypothesis: If different amounts of fertilizer is applied, then the bean plants will vary in height.

No Fertilizer 5% Fertilizer 10% Fertilizer 15% Fertilizer

15 plants 15 plants 15 plants 15 plants

Independent Variable:

Dependent Variable:

Height of Bean Plants in Centimeters

Constants:

Amount of water, light, soil, temperature, humidity, etc.