Independent Variable/Dependent Variable
What is an independent variable?
A variable being tested in an experiment.
What is a controlled variable?
A variable that is kept constant by the scientist in an experiment.
What is a control group?
The group that is exposed to "normal" conditions.
Once we have collected data from our experiment, and then analyzed it, what do we do next in order to begin presenting our findings to other scientists?
Make a claim that is one sentence in length and answers our problem statement.
What is repetition?
When one scientist makes multiple sets (or trials) of measurements or observations in a scientific investigation.
What is a dependent variable?
The outcome or measured results of an experiment.
Samara wants to test how sunlight affects the growth of plants, so she places one of them near a window, and one of them in a dark room. Each of the plants receive a cup of water each day.
What is the controlled variable of this experiment?
The amount of water the plants receive.
What is an experimental group?
A group exposed to the independent (test) variable.
After we have stated our claim, what do we need to present?
We need to present all scientific evidence from our data and research that supports our claim.
What is replication?
When different scientists reproduce a scientific investigation, originally completed by another scientist, in order to ensure accuracy.
Dashka wants to test how sunlight affects the growth of plants, so she places one of them near a window and one of them in a dark room. The plant by the window receives 1 cup of fertilizer each day, and the plant in the dark room receives no fertilizer. Each of the plants receives a cup of water each day.
Why is this not a strong experiment?
There is more than one independent variable.
Yvener would like to know if fish eat more food while they are listening to music. He designs an experiment to test his idea by measuring the amount of food consumed by the fish when they listen to music, and then when they do not listen to music, both for a 10 minute span of time.
In this experiment, what is the controlled variable?
The amount of time the fish eat for.
Dillan wants to test how different substances affect an organism's heart rate. He decides to use Daphnia as his test subject. He places one Daphnia into each of his three different containers. Each container has a different substance (caffeine, benadryl, and water). He then counts the number of heart beats of each Daphnia for 30 seconds.
What would be the control group for this experiment?
The daphnia placed in water.
After we have presented evidence from our data and research, what kind of information would we include in our reasoning?
We would include information that explains why our evidence is connected to supporting our claim.
Is the following repetition or replication?
Testing the Daphnia in Red Bull 3 times.
Repetition
Scheder wants to know whether drinking Red Bull or Monster will make it more difficult to fall asleep. He designs an experiment to test this problem statement.
In this experiment, the type of energy drink consumed is considered what type of variable?
The independent variable.
Gaetan wants to test how different substances affect an organism's heart rate. He decides to use Daphnia as his test subject. He places one Daphnia into each of his three different containers. Each container has a different substance. He then counts the number of heart beats of each Daphnia for 30 seconds.
What is one controlled variable mentioned above?
The amount of time for the heart beats to be counted, the type of organism
Aaliyah would like to know if fish eat more food while they are listening to music. She designs an experiment to test her idea by measuring the amount of food consumed by the fish when they listen to music, and then when they do not listen to music, both for a 10 minute span of time.
What would be the experimental group of this experiment?
The fish that are listening to music as they eat.
How long should your entire C-E-R be?
3 paragraphs
Is the following repetition or replication?
Joseph complete's Thomas's experiment by following all of the procedures that Thomas had followed.
Replication
Ashlene would like to know if fish eat more food while they are listening to music. She designs an experiment to test her idea by measuring the amount of food consumed by the fish when they listen to music, and then when they do not listen to music, both for a 10 minute span of time.
In this experiment, the amount of food the fish consume is what kind of variable?
The dependent variable.
Faith wants to know whether drinking Red Bull or Monster will make it more difficult to fall asleep. She designs an experiment to test this problem statement.
What is a controlled variable that the experiment may have?
Answers may include: The amount of Red Bull and Monster the person drank, the time they consumed the drink, the bed they slept in, the person consuming the beverages
David wants to know whether drinking Red Bull or Monster will make it more difficult to fall asleep. He designs an experiment to test this problem statement.
What would be the control group that David should use?
Testing how long it takes to fall asleep after consuming water.
When we are writing our C-E-R, what should our first paragraph include?
The purpose of our experiment, a restatement of our hypothesis as a prediction (claim), our independent and dependent variables, and a prediction of how our variables will change
Create and describe one example of repetition and one example of replication.
Up to teacher's discretion