Independent Variable
What is the independent variable in an experiment?
The one thing in an experiment that is changed by the scientist.
What is the dependent variable in an experiment?
The thing that is measured to see the effect of the independent variable.
What is a control group in an experiment?
A control group is the 'regular' version of an experiment. It doesn’t get the special changes you're testing.
What is the first step of the scientific method where scientists carefully observe the world around them?
Observation
Bonus: Give an example of an observation you could make that would lead you to an experiment.
True or False: Scientists only follow the scientific method when they are doing very large experiments.
False
In an experiment testing the how the reaction of sodium hydroxide, slime, and lemon juice changes when they are added in different orders, what is the independent variable?
The independent variable is the order of ingredients.
In an experiment testing the how the reaction of sodium hydroxide, slime, and lemon juice changes when they are added in different orders, what is the dependent variable?
The dependent variety is the height of the reaction and the time of the reaction.
In an experiment testing the how the reaction of sodium hydroxide, slime, and lemon juice changes when they are added in different orders, what is the dependent variable?
The control group is mixing sodium hydroxide and lemon juice without slime.
After making an observation, what is the next step where scientists figure out what they want to learn?
Question
Bonus: What is an example of a scientific question you could ask? Remember, a scientific question must be testable.
What do scientists write at the end of an experiment to explain what they learned?
Conclusion
Bonus: A scientist measures how fast ice melts in different temperatures. They find that ice melts fastest at 90°F, slower at 70°F, and hardly melts at all at 32°F. What is their conclusion?
A student is testing which type of paper towel absorbs the most water. What is the independent variable?
The brand/type of paper towel.
A scientist tests how different fertilizers affect how many tomatoes grow on a plant. What is the dependent variable?
The number of tomatoes that grow.
Why do scientists use a control group?
We use control groups to help us see if the change we made in the experiment is really causing the results.
What is a guess scientists make based on what they already know, that they test with an experiment?
Hypothesis
Bonus: What is the hypothesis format?
If a scientist’s hypothesis was wrong, what should they do next?
Think about what went wrong, make a new hypothesis, and try again.
Why is it important to only have one independent variable in an experiment?
So we know that any change in results is caused by that one thing and not something else.
What is the difference between an independent and a dependent variable?
The independent variable is what you change, the dependent variable is what you measure.
If you are testing how different drinks stain teeth, what would be a good control group?
A tooth soaked in water.
In the scientific method, what is the step where scientists create a test to see if their hypothesis is correct?
Experiment
Bonus: Why would your experiment need to be in clear and detailed steps?
Why is it important for scientists to write down and share their results?
So others can learn from them and check if they got the same results.
Think of an experiment you could do with water and temperature. First describe the experiment, then explain what your independent variable would be.
Variety of answers
Example: In an experiment changing water temperature to see how fast sugar dissolves, the temperature is the independent variable.
Bonus: what is the dependent variable in this experiment?
Think of an experiment using ice cubes. First describe the experiment, then explain what your dependent variable would be.
Variety of answers
Example: In an experiment testing how long an ice cube takes to melt at different temperatures, the dependent variable is the length of time for the ice cube to melt.
Bonus: what is the independent variable?
A student wants to see if a special shoe makes people run faster. What would be the control group in this experiment?
People running in their regular shoes.
Bonus: What would the independent and dependent variables be?
After doing an experiment, what do scientists need to carefully examine to figure out what happened?
Data Analysis
Bonus: When we swabbed different surfaces at Burgundy, how did we analyze our data?
You observe that a plant is growing more slowly in the shade than in the sunlight. What question might a scientist ask based on this observation?
Why does sunlight help plants grow faster?