The document describes the basic steps of the scientific method, which are observation, hypothesis, experiment, data collection, conclusion, and retesting. Observations involve noticing something in the natural world using the senses. A hypothesis is a suggested explanation for the observations that can be tested. An experiment is conducted to test the hypothesis by manipulating a variable and collecting data. A conclusion is then drawn about whether the hypothesis was supported based on the results. Retesting is done to verify the findings.

1. Scientific MethodScientific Method

2. Steps in the ScientificSteps in the Scientific
MethodMethod
 ObservationObservation
 HypothesisHypothesis
 ExperimentExperiment
 Data CollectionData Collection
 ConclusionConclusion
 RetestRetest

3. ObservationsObservations
 GatheredGathered
through yourthrough your
sensessenses
 A scientistA scientist
noticesnotices
something insomething in
theirtheir naturalnatural
worldworld

4. ObservationsObservations
 AnAn exampleexample of anof an
observationobservation mightmight
be noticing thatbe noticing that
many salamandersmany salamanders
near a pond havenear a pond have
curved, notcurved, not
straight, tailsstraight, tails

5. HypothesisHypothesis
 A suggestedA suggested
solution to thesolution to the
problem.problem.
 Must beMust be testabletestable
 Sometimes writtenSometimes written
asas If…Then…If…Then…
statementsstatements
 PredictsPredicts anan
outcomeoutcome

6. HypothesisHypothesis
 AnAn example of aexample of a
hypothesishypothesis mightmight
be that thebe that the
salamanders havesalamanders have
curved tails due tocurved tails due to
a pollutant in thea pollutant in the
moist soil wheremoist soil where
they live.they live.

7. ExperimentExperiment
 A procedureA procedure
toto testtest thethe
hypothesis.hypothesis.

8. ExperimentExperiment
VariableVariable ––
factor in thefactor in the
experimentexperiment
that is beingthat is being
testedtested

9. ExperimentExperiment
A good orA good or
“valid”“valid”
experimentexperiment
will only havewill only have
ONEONE
variable!variable!

10. Controls and VariablesControls and Variables

11. Scientific Experiments FollowScientific Experiments Follow
RulesRules
 An
experimenter
changes one
factor and
observes or
measures what
happens.

12. The Control VariableThe Control Variable
 The experimenter makes aThe experimenter makes a
special effort to keepspecial effort to keep otherother
factors constantfactors constant so thatso that
they will not effect thethey will not effect the
outcome.outcome.
 Those factors are calledThose factors are called
control variables.control variables.

13. What is the Purpose of aWhat is the Purpose of a
Control?Control?
 Controls are NOT being
tested
 Controls are used for
COMPARISON

14. Other Variables
 The factor that is changed is
known as the independent
variable.
 The factor that is measured or
observed is called the dependent
variable.

15. Example of Controls &Example of Controls &
VariablesVariables
 For example, suppose you want to figure
out the fastest route to walk home from
school.
 You will try several different routes and
time how long it takes you to get home by
each one.
 Since you are only interested in finding a
route that is fastest for you, you will do
the walking yourself.

16. What are the Variables inWhat are the Variables in
Your Experiment?Your Experiment?
 Varying the route is theVarying the route is the
independent variableindependent variable
 The time it takes is theThe time it takes is the
dependent variabledependent variable
 Keeping the same walkerKeeping the same walker
throughout makes the walker athroughout makes the walker a
control variable.control variable.

17. One more thing… it is best
to make several trials with
each independent variable.

18. Valid ExperimentsValid Experiments

19. Remember: To be a ValidRemember: To be a Valid
Experiment:Experiment:
 Two groups are required ---
the control & experimental
groups
 There should be only one
variable

20. DataData
 Results of the
experiment
 May be
quantitative
(numbers) or
qualitative

21. DataData
 Must be
organized
 Can be
organized into
charts,
tables, or
graphs

22. ConclusionConclusion
 The answer to
the hypothesis
based on the
data obtained
from the
experiment

23. RetestRetest
In order to
verify the
results,
experiments
must be
retested.

24. Solving a ProblemSolving a Problem
1)Identify a Problem
2) State Observations
about the problem
3) Form a Hypothesis about
the problem (if…then…)
4) Design an Experiment to
test the hypothesis
5) Collect Data
6) Form a Conclusion
7) Retest

25. RERUN
 R Restate the purpose of the
experiment. For some labs, you may
be given the purpose and for others
you may have to reword the question.
This can normally be completed in one
sentence. (The purpose of this lab
was to …).

26. RERUN
 E Summarize the experiment. What
did you do in this lab? Give enough
details that one with some science
background could follow the steps
with out much assistance. For some
labs, this can be completed in two or
three sentences. For other labs, it
may take six to eight sentences. (In
this lab we …).

27. RERUN
 R Analyze the results. Three main items should be
included in this section. First, restate the hypothesis. Next,
give actual data. Remember, this can be done with
quantitative and/or qualitative observations. Finally, state
whether the hypothesis was supported or rejected. You are
only conducting this experiment once. You will NOT be
able to prove any concept to be right, wrong, correct or
incorrect. This section of the RERUN will take a complete
paragraph to complete. If a lab has more than one
hypothesis, you may need more than one paragraph. (My
hypothesis was …). (The data shows …). And, (The
hypothesis was …).

28. RERUN
 U Describe any uncertainties or
problems that you had. What could
have gone wrong? You should be able
to complete this section in two or three
sentences. (One problem that I had
…). Or, (One thing that may have
gone wrong was …).

29. RERUN
 N What can you do now? How could
you apply this lab in your life? Or, how
could we change this lab in the future?
(One way to use in this information
would be …). Or, (One new thing I
learned was …).