1. Scientific Method
The scientific method is a series of steps taken during an experiment in order to solve a problem.

2. Why is the Scientific Method Important?*
07/16/96
Why is the Scientific Method Important?
Continuity
Communication within the scientific community 1 *

3. Steps of the Scientific Method
Observation
State the problem
Form a hypothesis
Experiment
Results/Data
Analysis 2

4. 3 Observations Qualitative observation Quantitative observation
Focus on the qualities of an object.
Ex. Color of an object
Quantitative observation
Characteristics of an object that can be measured.
Ex. Mass, Length 3

5. State the Problem
This problem or question is formed from your observations.
This is the question you as the scientist want answered.
Also called the “purpose”. 4

6. Form a Hypothesis
The hypothesis is a testable explanation to your problem.
“Educated Guess” is not enough. You must be able to test your explanation. 5

7. 6 Experiment Design an experiment that tests your hypothesis.
Control Group: test variables are kept constant
“Normal Conditions”
Experimental Group: variables are changed 6

8. Variables Variables – anything that changes throughout the experiment.
There are two types of variables:
Independent variable – the change that the experimenter controls.
Dependent variable – the change that is measured.

9. 7 Results/Analysis Results Analysis
This section includes all of the data and information collected.
How do you present your data?
Analysis
The data is explained and the process is wrapped up. 7

10. Spontaneous Generation – Life arises from non- living things
Redi’s experiment
OBSERVATIONS: Flies land on meat that is left uncovered. Later, maggots appear on the meat.
HYPOTHESIS: Flies produce maggots.
PROCEDURE
Uncovered jars
Covered jars
Controlled Variables:
jars, type of meat,
location, temperature,
time
Several
days pass
Manipulated Variables:
gauze covering that
keeps flies away from
meat
Responding Variable:
whether maggots
appear
Maggots appear
No maggots appear
CONCLUSION: Maggots form only when flies come in contact with meat. Spontaneous generation of maggots did not occur.

11. Figure 1-10 Spallanzani’s Experiment
Section 1-2
Gravy is teeming
with microorganisms.
Flask is
open.
Gravy is boiled.
Theory not supported “vital force in air was killed”
7/28/2018
Gravy is boiled.
Flask is
sealed.
Gravy is free of
microorganisms.

12. Pasteur’s Experiment Figure 1-11 Pasteur’s Experiment
Pasteur intro
Pasteur changed 1 variable in the experiment – he used a curved neck flask
Broth is boiled.
Broth is free of
microorganisms
for a year.
Curved neck
is removed.
Broth is
teeming with microorganisms.

13. Figure 1-11 Pasteur’s Experiment
The curved neck of the flask allowed air to mix in the jar but not bacteria
Section 1-2
Broth is boiled.
Broth is free of
microorganisms
for a year.
Curved neck
is removed.
Broth is
teeming with microorganisms.

14. Figure 1-11 Pasteur’s Experiment
Section 1-2
Broth is boiled.
Broth is free of
microorganisms
for a year.
Curved neck
is removed.
Broth is
teeming with microorganisms.

15. Figure 1-11 Pasteur’s Experiment
Once the neck was removed bacteria entered and spoiled the broth
Section 1-2
Broth is boiled.
Broth is free of
microorganisms
for a year.
Curved neck
is removed.
Broth is
teeming with microorganisms.

16. Assessment
Active Art Redi and Pasteur Assesment