Controlled Variables
What is a controlled variable?
A factor that stays the same in an experiment.
The variable you change on purpose is called the ______ variable.
Independent variable.
Which type of data uses numbers?
Quantitative data.
Discrete data is made up of separate, countable values. True or false?
True.
What is categorical data based on?
Categories, names, or labels.
Why do scientists keep controlled variables constant?
To make sure the experiment is fair and only the independent variable affects the results.
The variable you measure or observe is called the ______ variable.
Dependent variable.
Which type of data describes qualities or characteristics?
Qualitative data.
Give an example of discrete data.
Number of students in a class, number of eggs, number of cars, etc.
Categories, names, or labels.
Types of pets, colors, favorite foods, etc.
In a plant experiment, what are two examples of controlled variables?
Same type of plant, same amount of water, same soil, same pot, etc.
In an experiment testing how the amount of sunlight affects plant growth, what is the independent variable?
The amount of sunlight.
"The plant is 15 cm tall" is what type of data?
Quantitative.
Can discrete data include decimals or fractions?
No
What kind of graph is best for categorical data?
Bar graph or pie chart.
What could happen if controlled variables are not kept the same?
The results could be inaccurate or misleading.
In the same experiment, what is the dependent variable?
The plant’s growth (height).
"The plant’s leaves are green and smooth" is what type of data?
Qualitative.
Which type of graph is best for discrete data?
Bar graph.
What makes categorical data different from quantitative data?
Categorical = describes groups; Quantitative = uses numbers.
What’s another name for a controlled variable?
A constant.
What’s the difference between the independent and dependent variable?
Independent = changed by the scientist; Dependent = what is measured as a result.
Why is it helpful to collect both qualitative and quantitative data in an experiment?
It gives a more complete picture of the results.
What makes discrete data different from continuous data?
Discrete = countable; Continuous = measurable and can have decimals.
Can categorical data be ordered or ranked?
Sometimes — if it has a natural order (like small, medium, large).