Variables!

Objective:You will be able to identify independent

variables, dependent variables, and controls in an experimental set-up.

Itinerary:1. Review Definitions/Relate to Experiment

2. GAME!!3. Worksheet (finish for homework!)

Vocabulary Words

WordIndependent

Variable (IV)

Dependent Variable (DV)

Control

DefinitionWhat you change in an experiment (IV = I Change)What you measure in an experiment

The “normal” group that the experimental group is compared to

Picture

GameYou want to test the effect of different soaps on the growth of bacteria. You put dove on one dish of bacteria, dawn on another dish, and nothing on another dish. You measure how many bacterial colonies are growing after 4 days.Independent Variable:Dependent Variable:Control:

Different soapsGrowth of bacteria

Dish with no soap on it

GameBeth wants to see if eating bananas will make her run faster. She tests her speed on 3 different days. On day 1, she eats no bananas. On day 2, she eats 1 banana. On day 3, she eats 2 bananas. Each day, she times how long it takes her to run the mile.Independent variable:Dependent variable:Control:

Bananas

Run faster

Day 1 – no bananas

GameYou want to test the effect of colored light on the growth of marigolds. You set up five marigolds under blue light bulbs, five under red light bulbs, and five under normal growing lights. After 10 days, you measure how high they’ve grown.Independent variable:Dependent variable:Control:

Colored lights

Growth of marigolds

Plants with no light

GameYou want to see what type of paper makes paper planes fly farther than normal notebook paper.Independent variable:Dependent Variable:Control:

Types of paperFly farther

“normal” paper to make paper airplane

GameYou want to see what type of toothpaste makes teeth the whitest.Independent variable:Dependent Variable:Control:

Different toothpastes

Whitest teeth

No toothpaste or generic/plain toothpaste

Word Definition PictureThe parts of

the experiment

that you keep the

same every time you do it

Constant