the scientific method! a step by step guide for the rest of the year
TRANSCRIPT
The Scientific Method!
A step by step guide for the rest of the year.
The Scientific Method involves a series of steps that are used to
investigate a natural
occurrence.
Knowing and following
these steps are crucial to both this class and the TAKS
test!
Problem/Question
Observation/Research
Formulate a Hypothesis
Experiment
Collect and Analyze Results
Conclusion
Communicate the Results
Steps of the Scientific Method
1. Identify a Problem/QuestionProblem/Question: Must be
testable!!!!!!
2. Make Make observations and observations and
conduct researchconduct research: has anyone else looked at this problem?
Steps of the Scientific Method
3. Formulate a Formulate a HypothesisHypothesis: Predict a possible answer to the problem or question.
4. ExperimentExperiment: Develop and follow
a procedure.
Include a detailed materials list.
The outcome must be measurable (quantifiable).
Steps of the Scientific Method
5. Collect and Collect and Analyze ResultsAnalyze Results:
Modify the procedure if
needed.
Confirm the results by retesting.
6. ConclusionConclusion: Include a statement
that accepts or rejects the hypothesis.
Make recommendations for further study and
possible improvements to the
procedure.
Steps of the Scientific Method
7. Communicate the Communicate the ResultsResults: Be prepared to
present the project to an audience.
Expect questions from the audience.
The example
Lets take a basic problem and analyze it scientifically.
Problem/Question
Belton lake fish are dying in large numbers. Coincidentally a new Industrial plant has opened and has been discharging waste into the lake.
Observation/ResearchWe would research
the type of waste being discharged from the factory. Have any similar
cases been reported in the
past, etc, etc….
Formulate a Hypothesis
Textbook definition: The hypothesis is an educated guess about the
relationship between the independent and dependent
variables.
Formulate a Hypothesis
This can be tricky! Your hypothesis
must be simple, direct, and testable.
=
We will often use an experimental design template to keep track of
the details.
Design your experiment
Do you know the difference Do you know the difference between the independent between the independent and dependent variables?and dependent variables?
Independent Variable The
independent, or manipulated variable, is a factor that’s intentionally varied by the experimenter.
Example: We will add 5 mL, 10 mL, or 20 mL of toxic
waste.
Dependent Variable The dependent, or
responding variable, is the factor that may
change as a result of changes made in the independent
variable.Example: the number of
dead fish.
Other Details of the Experiment
A clear procedure so that someone can replicate your experiment.
A list of required materials so they use the correct equipment.
Other Details of the Experiment
In a scientific experiment, the control is the group
that serves as the standard of comparison.
The control group usually is exactly the same as the test groups but the Independent variable is absent or set to “zero”
No toxic sludge in the control!
Control Group
The control group is exposed to the same conditions as the
experimental group, except for the variable being tested.
All experiments should have a control group.
Trials
Trials refer to replicate groups
that are exposed to the
same conditions. This
will eliminate “freak”
outcomes.
ConstantsRemember! In a valid
experiment the only things that should
change from trial to trial are the
independent and dependent variables!
Can you think of some Can you think of some constants for this constants for this
experiment?experiment?
Collect and Analyze ResultsData should be clear
and organized.
A Data table should be drawn BEFORE the
experiment is conducted.
Toxic waste and fish mortality
Amt. of waste
1 2 3 AverageAverage
deathsdeaths
0 mL 1 0 0 0.33
5.0 mL 2 1 2 1.7
10.0 mL 5 4 6 5
20.0 mL 8 11 9 9.3
Number of dead fishNumber of dead fish
TrialsTrials
Control group
Can you accept or reject Can you accept or reject your hypothesis?your hypothesis?
Communicate the Results
You now have hard data that supports your hypothesis.
This is hard to argue against!