Question

name: zach
goal: to demonstrate student understanding of independent and dependent variables
procedure - part i: identify the dependent and independent variable in each of the eight investigations below. remember the following definitions:
independent variable: the factor controlled (or changed) by the experimenter. this might also be described as the change made by the experimenter on purpose. it is sometimes called the manipulated variable.
dependent variable: the factor (or result) which changes because of what the experimenter does. the dependent variable is the change that occurs because of what the experimenter does; it gets changed by the independent variable. it is sometimes called the responding variable.
example: you are investigating how soil type influences bean stem growth. in your investigation...
a. independent variable (the variable that you are controlling) is types of soil used.
b. dependent variable (the results) would be the growth of bean stems.

1. is plant growth affected by the color of light in which it grows?

a. independent variable:
b. dependent variable:

1. which laundry detergent removes stains more effectively?

a. independent variable:
b. dependent variable:

1. does the type of oil affect the size of popcorn?

a. independent variable:
b. dependent variable:

1. which type of paper towel is more absorbent?

a. independent variable:

1. which battery has the longest life span?

a. independent variable:
b. dependent variable:

1. which paint resists weathering more effectively?

a. independent variable:
b. dependent variable:

1. do different types of music affect student math accuracy?

a. independent variable:
b. dependent variable:

1. how do different salts affect the melting point of ice?

a. independent variable:
b. dependent variable:
part ii: evaluation

1. explain how you know which variable in an experiment is the independent variable.

Explanation:

Step1: Identify independent variable for 1

The experimenter controls the color of light, so it is the independent variable.
a. Independent variable: Color of light

Step2: Identify dependent variable for 1

Plant growth changes based on the color of light, so it is the dependent variable.
b. Dependent variable: Plant growth

Step3: Identify independent variable for 2

The experimenter chooses the laundry - detergent, so it is the independent variable.
a. Independent variable: Type of laundry detergent

Step4: Identify dependent variable for 2

Stain - removal effectiveness depends on the detergent, so it is the dependent variable.
b. Dependent variable: Stain - removal effectiveness

Step5: Identify independent variable for 3

The experimenter selects the type of oil, so it is the independent variable.
a. Independent variable: Type of oil

Step6: Identify dependent variable for 3

The size of popcorn changes with the type of oil, so it is the dependent variable.
b. Dependent variable: Size of popcorn

Step7: Identify independent variable for 4

The experimenter chooses the type of paper towel, so it is the independent variable.
a. Independent variable: Type of paper towel

Step8: Identify dependent variable for 4

Absorbency depends on the type of paper towel, so it is the dependent variable.
b. Dependent variable: Absorbency

Step9: Identify independent variable for 5

The experimenter selects the battery type, so it is the independent variable.
a. Independent variable: Type of battery

Step10: Identify dependent variable for 5

Battery life - span depends on the battery type, so it is the dependent variable.
b. Dependent variable: Battery life - span

Step11: Identify independent variable for 6

The experimenter selects the paint type, so it is the independent variable.
a. Independent variable: Type of paint

Step12: Identify dependent variable for 6

Weather - resistance depends on the paint type, so it is the dependent variable.
b. Dependent variable: Weather - resistance

Step13: Identify independent variable for 7

The experimenter selects the type of music, so it is the independent variable.
a. Independent variable: Type of music

Step14: Identify dependent variable for 7

Student math accuracy changes with the type of music, so it is the dependent variable.
b. Dependent variable: Student math accuracy

Step15: Identify independent variable for 8

The experimenter selects the type of salt, so it is the independent variable.
a. Independent variable: Type of salt

Step16: Identify dependent variable for 8

The melting point of ice changes with the type of salt, so it is the dependent variable.
b. Dependent variable: Melting point of ice

Answer:

1.
a. Color of light
b. Plant growth
2.
a. Type of laundry detergent
b. Stain - removal effectiveness
3.
a. Type of oil
b. Size of popcorn
4.
a. Type of paper towel
b. Absorbency
5.
a. Type of battery
b. Battery life - span
6.
a. Type of paint
b. Weather - resistance
7.
a. Type of music
b. Student math accuracy
8.
a. Type of salt
b. Melting point of ice