1.1.2 The Scientific Method
Process of the Scientific Method
Learning Objectives - Biology
Definition of the term Biology?
Name and explain at least three areas of study
incorporated in Biology?
Definition for Biology
BIOLOGY is the study of living things
Biology has many different areas of study








Anatomy
Biochemistry
Botany
Ecology
Genetics
Microbiology
Physiology
Zoology
Anatomy
 The study of the
internal and external
structure of plants
and animals
Biochemistry
 The study of the
chemical processes
and products
involved in
metabolism
Mikael Haggstrom – Wikimedia Commons
Botany
 The study of plant
structure,
physiology,
distribution and
classification
Learning Objectives – Scientific Method
 State the process of the Scientific Method
 State the limitations of value of the Scientific
Method
 State some possible sources of errors
8
The Scientific Method
 The scientific method is a way to solve a
problem
 This is the method on which all projects
should be based.
9
The Scientific Method
The Scientific Method involves the following steps:






Making observations
Formulating a hypothesis
Designing a controlled experiment
Collecting and interpreting data
Forming a conclusion
Comparing the conclusion with existing
knowledge
 Reporting and publishing the results
 Developing theories and principles
10
Steps in the scientific method
Observation
• You observe something using your senses
Question
• You ask a question about what you
observed. State it as a problem or question
Hypothesis
Prediction
Test
•.
• Hypothesis: a testable‚ tentative answer to
a question
• You predict what you think the answer to
your question might be.
• You design a way to test whether your
hypothesis is correct or not.
• Record and analyze data
Results
• You do the experiment(s) using the method you
came up with and record the results.
Conclusions
• You state whether your prediction was
confirmed or not and try to explain your results.
Compare
• Compare your findings to existing knowledge
11
Observation
 You observe something using your senses or
machines which are basically extensions of
those senses.
12
Question
 You ask a question about what you observed.
State it as a problem or question.
13
Learning check
 What are the steps in the Scientific Method?
14
Hypothesis
 Hypothesis: a testable‚ tentative answer to
a question
(hypo = under‚ beneath; thesis = an
arranging)
You predict what you think the answer to your
question might be. The hypothesis is a
testable explanation for what was observed.
The scientist tries to explain what caused
what was observed.
15
Experiment
 You figure out a way to test whether your
hypothesis is correct or not. The outcome
must be measurable. (quantifiable)
 Record and analyze data.
16
Result
 You do the experiment(s) using the method
you came up with and record the results.
 You repeat the experiment to confirm your
results.
17
Learning check
What is the next step?
 The Conclusion
18
Conclusion
 You state whether your prediction was
confirmed or not and try to explain your
results.
19
Compare
 You compare your conclusion with existing
knowledge.
20
Finally
 You Report and Publish your results.
 You Develop a theory or principle.
21
Need to know
 State the process of the Scientific Method
Explain the following:
 Observation
■ Hypothesis
 Design Experiment
 Record & Analyze Data
 Conclusions
 Compare to Existing Knowledge,
 Reporting
■ Theory ■ Principle
22
1.1.2 The Scientific Method
Limitations of the Scientific Method
The Scientific Method
 Is limited by the extent of our basic knowledge
 Is limited by our ability to interpret the results
 is limited to what can be observed with the five
senses e.g., what existed prior to the Big Bang and
the known universe is outside of the realm of science
to investigate
 is limited by the changes in the natural world
24
Limitations of the Scientific Method
 tells us “how” a process works, not “why” e.g., does
not really explain why the Universe exists
 inability to answer value-based questions involving
“should”
 may be affected by the emotional involvement of
investigator
 may be affected by time pressure for results
25
Limitations of the Scientific Method
 inability to capture the full richness and
complexities of the participants
 limitations of our measurement instruments
 ethical and legal responsibilities
 Religious beliefs
 we can never be sure all untested variables
are controlled
26
Limitations of the Scientific Method
 conclusions based on the experimental data
must remain tentative
 human personality traits are part of “real
science”
 scientists sometimes make mistakes
 accidents, lucky guesses, intellectual powers,
and controversies with others contribute
strongly to scientific advances
27
Need to know
 State the limitations of value of the Scientific
Method
28
Learning objectives Experimentation
Can you state about eight principles of
experimentation?
Planning & Design
Random Selection
Safety Procedure
Replicaton
Control Experiment
Double-Blind Testing
Sample Size
Sources of errors
29
What is an experiment?
1. An experiment is a controlled test.
2. Only one variable should be changed at a time.
a. Independent variable – changed by the
experimenter.
(Hint: I change the Independent variable)
b. Dependent variable (Responding) – the effect.
30
What is an experiment?
3. Constants do not change.
4. Controlled variables are those which could
change, but are not allowed to.
5. Two parts to an experiment:
a. Control group – normal conditions.
b. Experimental group(s) – variables are
changed.
6. Prediction is the goal of experiments.
31
How to organise an experiment
OR
The Principles of Experimentation
1. Plan and design
2.
3.
4.
5.
the experiment
Be aware of Safety
procedures
Select organisms
at random
Use a large
enough sample
size
Use a control
group
6. Use Double-blind
testing
7. Change one factor
at a time
8. Measure changes
9. Analyze the results
10. State possible
sources of error
11. Repeat the
experiment
32
Learning check
What is an experiment?
 It is a controlled test where only one variable
is changed at a time.
33
An example of an experiment
Observation: It has been suggested that large
daily doses of Vitamin C protect against the
common cold virus.
Hypothesis: Vitamin C protects against the
common cold virus
34
An example of an experiment
Experiment design: Ten adult males in their
mid twenties who are friends of the
investigator were chosen to test the possible
value of vitamin C.
5 of them were given 3000mg of vitamin C a
day; the other 5 were given a placebo.
Which is the control group?
Which is the experimental group?
Is this a good experiment?
35
Problems with experiment design
All males
All mid twenties
All friends
Not a large enough sample
36
A Good Experiment
Should

Have only one variable

Use a large number of samples

Use random selection

Be repeated

Use double blind testing
37
Learning objectives
Experimentations
Can you state about eight principles of
experimentation?
Planning & Design
Random Selection
Safety Procedure
Replicaton
Control Experiment
Double-Blind Testing
Sample Size
Sources of errors
38
END
39