Manipulating Variables

Students were involved in an experiment to investigate whether playing music while they took a test affected their scores. What would their test scores be?

• Independent variable
• Dependent variable
• Controlled variable
• Hypothesis

This is the manipulated variable, or the variable you control or change

• Independent
• Dependent

This is the responding variable, or the variable you measure

• Independent
• Dependent

The factor being tested in an experiment is the ... 

• variable
• hypothesis
• control
• research

If you were running an experiment to determine the temperature at which beans sprout the fastest, what would be the independent variable?

• The number of beans you plant
• The height of the sprouts you grow
• The amount of water you give the beans
• The temperature at which each bean is kept

A student hypothesized that robins prefer large birdhouses to small ones. He build four birdhouses of different sizes to test his hypothesis. What was the independent variable in the students study?

• The size of the birdhouse
• The number of birds in the house
• The location of the birdhouse
• The season of the year

It is January, and Haley and Sarah are tired of cold feet.  They decide to design and experiment looking at the effectiveness of wool versus cotton versus nylon as insulators.  They fill identical water bottles with 100⁰F water and put them in each different type of  sock, and measure the temperature every 20 mins.  What is the independent variable being measured. 

• Water Temperature
• Type of sock used
• Amount of water
• Month of the year

A group of middle school students were given a short course in speed reading.  The teacher was curious of money could influence their performance on a test taken at the end of the course.  Half the students were offered $5 for a getting a certain percentage better at speed reading, the other half was offered no money.  Which is the dependent variable.

• Students being offered money or not.
• Their test  scores.
• Their age in school years.
• The length of the course.

A teacher wanted to see how different types of music affected students pulse rates.  She played, country, rap, rock, jazz, and classical, and measured the students pulses for 10 mins each.  What is the independent variable?

• pulse rate
• type of music
• length of time measuring pulse
• age of student

Nick wanted to see how high an ice cube would float in in different temperatures of water.  What is the dependent variable?

• size of the ice cube
• amount of water
• water temperature
• height of ice cube floating