an organized approach to solving problems scientific method
TRANSCRIPT
AN ORGANIZED APPROACH TO SOLVING PROBLEMS
SCIENTIFIC METHOD
Scientific Method
Organized problem solving• Not a single method
Steps of the Scientific Method
1. Define the Problem2. Collect Information About the Problem3. Form a Hypothesis4. Experiment5. Collect Results6. Conclusion7. Repeat
Step 1. Problem
What are to trying to find out? - Usually based on observations - stated as a question
Example: I notice that on warm nights crickets seem
to chirp more often
Problem = Does temperature affect the rate of cricket chirps?
Step 2. Collect Information About the Problem
Information can be gathered from: - your own observations
- published research textbooks, articles, internet etc…
Step 3. Form a Hypothesis
A possible solution to your problem
Must make a prediction
Must be possible to be disproved - UFOs exist is not a scientific hypothesis
because it is impossible to disprove
Formal Hypothesis
A formal hypothesis used in an experiment should be stated in If…Then form.
- It relates directly to the experiment to be conducted and explains the expected outcome
-If I do this…..then that will happen.
Example: If I raise the temperature I keep crickets in, then they will chirp more.
Step 4. Test Your Hypothesis-Experiment
Experiment must be controlled
- tests only one thing at a time
A controlled experiment compares a control group with an experimental group
The control group provides a normal standard against which the biologist can compare results of the experimental group.
The experimental group is identical to the control group except for the one factor being tested
- the variable being tested is the independent variable
Experimental Design
Needs to be repeatable
Should test a large sample
Should be without bias
Variables
Variable = anything that can change in an experiment
Controlled variables = What do I keep the same?
Independent variables = What do I change?aka Manipulated variables
Dependent variables = What do I measure? aka Responding variables
Question Independent Variable(What I change)
Dependent Variables (What I observe)
Controlled Variables (What I keep the same)
How much water flows through a faucet at different openings?
Water faucet opening (closed, half open, fully open)
Amount of water flowing measured in liters per minute
•The Faucet •Water pressure, or how much the water is "pushing" "Different water pressure might also cause different amounts of water to flow and different faucets may behave
Control Group Experimental Group
20 crickets grown in a 10 gallon aquarium
12 hours of light/day
Fed 5 g Acme Cricket Food
Kept at 60 degrees F
20 crickets grown in a 10gallon aquarium
12 hours of light/day
Fed 5 g Acme Cricket Food
Kept at 80 degrees F
Cricket Experiment
Step 5 Data and Results
Data = observations or measurements - Quantitative = number data 10 chirps/minute - Qualitative = observations color changed to orange
Results = Processed data – makes the meaning of the data more clear. Allows you to see trends or patterns. Calculate an average, graph of data etc..
Graphing Your Data
Independent Variable- the factor that is changed before the experiment begins. It goes on the x-axis. Sometimes called manipulated
Dependent Variable- the factor that you ran the experiment to measure, sometimes called results. It goes on the y-axis. Sometimes called responding
Sample Graph
Dependent Variable: on the Y Axis
Independent Variable on the X Axis
Conclusions
Was your hypothesis correct? - do the results support your hypothesis What are possible sources of error? What next? – What question could you study
next? Why is this important?
Repeat Your Work/Publish
Repeat experiment to confirm your results.
When scientists have completed their work, they publish their results - this informs other scientists of their findings
Theory
A hypothesis that has been tested repeatedly and shown to be correct becomes a theory
Theories can explain current observations and predicts new observations
A theory is as close to certainty as you get in science
Vocabulary to Know and Love
hypothesisexperimental groupcontrol groupvariablecontrolled variablesindependent/manipulated variableDependent/responding variabledataquantitative dataqualitative dataResultstheory