1. Scientific Method
How Scientist Work

2. How Scientists Work: Solving the Problems
Much of science deals with solving problems.
These problems can be environmental, ecological, health related, etc.
No matter what types of problems are being studied, scientists use the same problem-solving steps called…
the Scientific Method.

3. Scientific Method Definition
The scientific method is-
A logical and systematic approach or process to problem solving. 
An organized way of using evidence to learn about the natural world.
According to Wikipedia – the scientific method is a body of techniques for investigating phenomena and acquiring new knowledge, as well as for correcting and integrating previous knowledge. It is based on gathering observable, empirical and measurable evidence subject to specific principles of reasoning, the collection of data through observation and experimentation, and the formulation and testing of hypotheses.

4. Scientific Method Listing the Steps
Make an Observation
Define the Problem
Research the Problem
State the Hypothesis
Experiment to Test Hypothesis
Collect and Record Data
Analyze Data
Draw Conclusions
Determine Limitations
Report Results
If needed, do more investigation.

5. Scientific Method An Overview Question Research Hypothesis Procedure/
First
What does the scientist want
to learn more about?
Then
Research
Gathering of information
Next
Hypothesis
An “Educated” guess of an
answer to the question
Then
Procedure/
Method
Written and carefully
followed step-by-step
experiment designed to test
the hypothesis
Scientific Method
An Overview
Next
Data
Information collected during
the experiment
And
And
Observations
Written description of what
was noticed during the
experiment
Finally
Conclusion
Was the hypothesis correct
or incorrect?

6. Here is another example of how the steps may go….
Form a
Hypothesis
Make
Observations
Define / Identify
the Problem
Test Hypothesis
Perform Experiments
New
Experiments
Do Experiments
and Observations
Support Hypothesis?
YES
Organize and
Analyze Data
Draw Valid
Conclusions NO
Communicate
Results
Faulty
Experiments?
Here is another example of how the steps may go….
Even though we show the scientific method as a series of steps, keep in mind that new information or thinking might cause a scientist to back up and repeat steps at any point during the process.

7. 1. Observing Make an observation See something unusual
As we all know, frogs have four legs.
Make an observation
See something unusual
Frogs with incorrect number of legs!
What’s up with these froggies?

8. 2. Questioning Recognize, state or define the problem
Must be in the form of a question
The obvious question is: 
What is causing these deformities?

9. 3. Researching Gather information related to the problem
Read, observe, measure, take samples, etc.
How frogs normally develop from eggs
The % of frogs with the deformities
Number of other species in the pond with deformities
Previous or new pollutants in the pond
A change in the amount of UV (sunlight) exposure on eggs

10. 4. Hypothesizing A hypothesis is:
An educated guess, trial answer, possible solution, prediction
Must be a statement
Must be testable or measurable
Is based on your research and previous experience

11. Hypothesizing (cont).
List possible explanations (alternative hypotheses) based on your previous experience (what you already know) and on research you have done  
all of the hypotheses must be testable

12. Hypothesizing (cont.)
Aliens from Outer Space-
Sorry, this is not allowed because it is not testable using the Scientific Method.  Sheesh!
Something Else- Another possibility that we might think of is predation or cannibalism, which seems to be the best explanation for certain kinds of deformities (frogs with missing limbs).
If this hypothesis is true, then, at minimum:
We should find frogs and/or other pond critters with evidence that their legs have been damaged or bitten off
Loud Rock + Roll Music- Okay, this is testable, but WHY test it??? (get real)
Disease (virus, parasite, etc.)-
If this hypothesis is true, then:
We should be able to find the disease-causing agent (for example, parasites) at the deformed frog ponds
We should be able to find the parasites in the deformed frogs
We should be able to use the same parasite to induce the exact same kinds of deformities in the lab
Ultraviolet Radiation- If this hypothesis is true, then:
We should be able to measure unusually high levels of UV radiation at deformed frog sites
We should be able to use these same levels to induce the exact same kinds of deformities in the lab
Can you think of other predictions based on this hypothesis?
Chemical Pollution- If this hypothesis is true, then:
You should be able to find a likely chemical pollutant in the deformed frog ponds
You should be able to isolate the chemical from the pond water
You should be able to show that the isolated chemical can cause the exact same deformities in the lab
These are minimal predictions;  you may have already thought of the fact that chemical pollution should affect all four limbs equally, or that other organisms from the same ponds should show deformities as well
Genetic Mutation-
If this hypothesis is true, then:
If we mate deformed frogs the offspring should show similar deformities
The deformities should be fairly uniform and predictable
The particular deformities should only be found in one species
Some possible explanations (hypotheses) for the frog deformities: Genetic Mutation
Chemical Pollution
Ultraviolet Radiation
Disease (virus, parasite or...?)
Loud Rock & Roll Music
Aliens From Outer Space
or Something Else

13. 5. Experimenting When testing the hypothesis:
Pick the hypothesis that makes the most sense and is easy to test
Then design a controlled experiment

14. Experimenting (cont.)
Go to the web site for Hartwick College to see the experiments and how the scientific method was actually used to find out the cause of recently found frog deformities.

15. Experimenting (cont.)
Let’s look at another example of the scientific method using Redi’s experiment on spontaneous generation
He was trying to disprove the idea of spontaneous generation (or prove that flies actually came from maggots, which came from flies)
Francesco Redi (1668)

16. Stating the Problem Example: How do new living things come into being?
Spontaneous generation once was commonly accepted
Redi wanted to show what caused the appearance of maggots (and then flies) on meat

17. (Untrue) Beliefs Based on Prior Observations
If a leaf landed on water it became a fish
If a bale of hay was left in a barn it produced mice
If it rained worms fell from the sky

18. Belief Based on Prior Observations
Redi observed that maggots appeared on meat a few days after flies were on meat
No microscope = no way to see eggs
But Redi believed that maggots came from eggs that were laid by flies

19. Forming a Hypothesis Redi’s Hypothesis: Flies produce maggots.
How could he test this?
Through a controlled experiment

20. Redi’s Controlled Experiment
Redi used two groups of jars
Jars that contained meat and no cover
Jars that contained meat and a gauze cover
Jars with meat
Uncovered jars
Covered jars

21. Control and Experimental Groups
used as a standard of comparison
the group containing the factor (variable) that has been changed
Control group:
Experimental group:
Two groups of jars
Uncovered jars
Covered jars

22. Variables in an Experiment
Variables - Factors that can be changed
Controlled Variables - all the variables that remain constant
Manipulated Variable - (also called the Independent Variable) - factor in an experiment that a scientist purposely changes
Responding Variable- (also called the Dependent Variable) - the outcome or results; factor in an experiment that may change because of the manipulated variable…. what a scientist wants to observe

23. Setting Up a Controlled Experiment
In a controlled experiment, only one factor is changed at a time.
Independent Variable: the factor that is deliberately changed
Dependent Variable: the factor that the scientist wants to observe; it changes in response to the independent variable

24. Variables in Redi’s Experiment
Controlled Variables: jars, type of meat, location, temperature, time
Manipulated Variable: gauze covering that keeps flies away from meat
Dependent Variable:
growth of maggots

25. Let’s think about this.…
Which is the control group?
Which is the experimental group?
Uncovered jars
Covered jars
Two groups of Jars with meat
Uncovered jars
Covered jars

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

27. 6. Collect and Record Data
observations and measurements made in an experiment
2 Types of Recorded Data
Quantitative - observations that involve measurements/numbers; i.e. 3 days, 12 maggots, 4 g, 13 sec, 8 liters
Qualitative - observations that do not involve numbers, are of a descriptive nature i.e. white maggots covered the meat, leaves were all wilting
**Observations involve using the 5 senses.

28. 7. Analyze the Data Examine data tables, charts, and graphs
Examine experimental notes
Look for trends, patterns, and averages
What does the data show
Put your data into words

29. 8. Draw Conclusions Restate the hypothesis:
Example: Flies produce maggots.
Accept or reject the hypothesis.
Support your conclusion with specific, numerical data.
What was Redi’s conclusion?
Flies lay eggs too small to be seen.
Maggots found on rotting meat are produced
from the eggs laid by flies.
Maggots are not appearing due to spontaneous generation!

30. 9. Determine Limitations
Scientists look for possible flaws in their research
They look for faulty (inaccurate) data
They look for experimental error or bias's
They decide on the validity of their results
They make suggestions for improvement or raise new questions

31. 10. Publish Results Communication is an essential part of science
Scientists report their results in journals, on the internet, or at conferences
This allows their experiments to be evaluated and repeated
Scientists can build on previous work of other scientists
Redi’s experiment
on insect generation

32. Repeating the Investigation
Sometimes results are unexpected.
John Needham challenged Redi’s experiment and designed his own to show that spontaneous generation CAN occur under certain circumstances.
Lazzaro Spallanzini designed a slightly different experiment to improve on Needham’s work
Repeat the experiment!

33. Repeating the Experiment (continued)
Louis Pasteur further modified the experiment.

34. Scientific Method How Scientists Work Solving the Problems
The reason scientific work is called “RE-search” rather than just "search " is because it is an ongoing process that often times changes our view of the natural world. It is subject to modification in light of new evidence and new ways of thinking.

35. Can you put these steps in order?
Define the Problem 2
Analyze Data 7 10 8 6
Report Results
Make an Observation
State the Hypothesis 1 4
the Problem 5 9 3
Determine Limitations

36. Steps of Scientific Method in order1
State the Hypothesis
Make an Observation
Define the Problem 2
the Problem 3 4 5 6
Analyze Data 7 8 9 10
Report Results
Determine Limitations

37. Scientific Theory
A theory is an explanation of a set of related observations or events based upon proven hypotheses and verified multiple times by detached groups of researchers.

38. Scientific Law
Scientific Method
Scientific laws represent the cornerstone of scientific discovery
They must be simple, true, universal, and absolute
If a law ever did not apply, then all science based upon that law would collapse