Nature of Science/Experimental Variables

Carmen conducted an experiment to determine if listening to different types of music would affect a person’s pulse. Her hypothesis was that pulse rate would change with different types of music. Each person listened to seven different selections of music for 30 seconds each. Each person’s pulse was taken before the music and then after each 30-second interval of music. The pulses were taken again after the music selections were completed. Based on her experiment, Carmen concluded that a person’s pulse rate changed when the person listened to different types of music. What is Carmen missing from her experiment?

• a question
• a hypothesis
• a control group
• a description of the experiement

When experimenting with the growth of a plant, a scientist uses three (of the same type of) plants, two different fertilizers, equal light, and equal water. What type of variable is the fertilizer?

• Dependent
• Independent
• Control
• Constant

Tags

NGSS.MS-LS1-5

Should experiments be repeated over and over to see if the results are the same each time?

• yes
• no

a procedure of steps carried out under controlled conditions to test a hypothesis/answer a question

• model

• investigation

• experiment

• research

Tags

NGSS.MS-ETS1-4

a factor that is not changed in an experiment; all the parts that stay the same to keep the experiment fair and consistent

• variable

• control group

• constant

• evidence

Which of these questions would be part of a true scientific experiment?

• What happens when you add Mentos to coke?

• Does the type of salt affect the fluffiness of the cake?

• What is the best soda brand?

• How do you make homemade play-doh?

Which is the best scientific question?

• Who prefers multicolored bouncy balls over solid colored bouncy balls?

• What makes a ball bounce?

• Why do some bouncy balls bounce higher than others?

• Does increasing the temperature of a bouncy ball change the height it bounces?

Tags

NGSS.MS-PS3-4

NGSS.MS-PS3-5

The factors that are different because they are responding to the experiment, not because the person experimenting changed them are:

• Controls

• Independent variables

• Observations

• Dependent variables

A control is:

• Something kept the same in an experiment.

• Something changed in an experiment.

• A standard of comparison in an experiment (the normal).

• Not a part of experimental design.

Ms. Frizzle wanted to know what color flower attracted the most butterflies. She already had white flowers planted, but she added red and purple flowers to her garden. Every day she watched the flowers from 10 -11 in the morning and counted how many butterflies landed on each colored flower. Each flower was planted in the band courtyard and was watered at 3:30 every day.

Number of butterflies is the ______________

• independent variable

• constant

• dependent variable

• control

Tags

NGSS.MS-LS2-4