Download The Scientific Method

The Scientific
Method
What is the Scientific
Method?
A set of steps
or procedures
that you follow
when
conducting an
experiment.
OBSERVATION &
Asking a Question
Use the 5 senses to
record what you observe.
Then turn your
observations into a
question.
HYPOTHESIS
A proposed scientific
explanation. This statement is
testable and can be confirmed with
experimentation or further
observation.
PREDICTION
 Forecast
what will happen in an
experiment if the hypothesis is true
 Written in an if-then statement
Which box represents
observations?
A
B
causes the
victims to die?
•How is it
transmitted?
•What might differ
between these
investigations?
In 1976 an outbreak in South Africa
started with individuals suffering
from severe headaches, fevers,
bloody diarrhea, and vomiting.
Eventually they suffered from
internal bleeding with blood leaking
from the nose, ears, and skin.
Finally death came from collapse of
the cardiovascular system due to
lack of blood.
•What
C
If the virus were the causing
agent, then introduction of the
virus into healthy tissue would
cause cell death.
D
The virus is
isolated from a
victim causes the
hemorrhagic
fever.
Which box represents observations?
Observation (B)
In 1976 an outbreak in South Africa
started with individuals suffering
from severe headaches, fevers,
bloody diarrhea, and vomiting.
Eventually they suffered from
internal bleeding with blood leaking
from the nose, ears, and skin.
Finally death came from collapse of
the cardiovascular system due to
lack of blood.
Which box represents questions?
A
•What
causes the
victims to die?
•How is it
transmitted?
•What might differ
between these
investigations?
C
If the virus were the causing
agent, then introduction of the
virus into healthy tissue would
cause cell death.
D
The virus is
isolated from a
victim causes the
hemorrhagic
fever.
Which box represents observations?
Observation (B)
In 1976 an outbreak in South Africa
started with individuals suffering
from severe headaches, fevers,
bloody diarrhea, and vomiting.
Eventually they suffered from
internal bleeding with blood leaking
from the nose, ears, and skin.
Finally death came from collapse of
the cardiovascular system due to
lack of blood.
Questions (A)
•What
causes the victims to
die?
•How is it transmitted?
•What might differ between
these investigations?
Which box represents a
Hypothesis?
C
If the virus were the causing
agent, then introduction of the
virus into healthy tissue would
cause cell death.
D
The virus is
isolated from a
victim causing the
hemorrhagic
fever.
Which box represents observations?
Observation (B)
In 1976 an outbreak in South Africa
started with individuals suffering
from severe headaches, fevers,
bloody diarrhea, and vomiting.
Eventually they suffered from
internal bleeding with blood leaking
from the nose, ears, and skin.
Finally death came from collapse of
the cardiovascular system due to
lack of blood.
Hypothesis (D)
The virus is isolated from a
victim causes the hemorrhagic
fever.
Questions (A)
•What
causes the victims to
die?
•How is it transmitted?
•What might differ between
these investigations?
Prediction (C)
If the virus were the causing
agent, then introduction of the
virus into healthy tissue would
cause cell death.
MINI LAB:
CAN SCIENTIFIC METHODS
BE USED TO SOLVE A
PROBLEM?
EXPERIMENT
Test the hypothesis and
prediction
EXPERIMENT
A. Controlled experiment: has a control group
and an experimental group differing by only
one factor (variable).
•
–
Constants: Variables that remain the same
between the experimental and control groups.
Ex. When testing the effects of fertilizer on fruit
production, everything would stay the same between two
groups of plants (water, sunlight exposure, amount of
fertilizer etc). They only difference is the type of fertilizer.
 This way any difference seen between the two plants would
have to be due to the fertilizer.
EXPERIMENT
B. Independent vs Dependent Variable
• Independent (cause): variable scientists
change or manipulate
• Dependent (effect): changes as independent
changes. The variable you are measuring.
Ex: Scientists control fertilizer type given to plant
(independent variable), but have no control over how
many fruits the plant produces (dependent).
EXPERIMENT
C. Collecting data (information scientist gather)
• Observations and measuring
• Sampling (using a small part to represent a bigger
part) must be large and random
• Quantitative (numerical and objective) vs qualitative
(observed or descriptive and subjective) data.
Ex. Fruit color would be
qualitative data whereas the
number of fruits produced
would be quantitative data.
DATA ANALYSIS
– Organize data (tables, graphs, etc.)
– Run statistics and model data
– Accept or reject hypothesis
Draw or form
CONCLUSION
– Explain data, results,
hypothesis
– Make inferences
– Summarize
experiment and form
new questions
COMMUNICATE
Share your findings
with other scientists.
Talk
Internet
Write