Variables and Controls Day 1

So Let’s Begin, Shall We? What are variables and constants?

What is changed by the Independent Variable What stays the same What I change Woke up on time Hit the snooze button Made it to school on time Missed the bus Bus came at the same time Bus came at the same time

Variables and Controls Day 2

Independent Variables

(Variables and Controls) SPI 0807.Inq.1 (Variables and Controls) Notes Science Variables and Controls in Experiments Used with the scientific method Step 1: Make Observations Step 2: Ask A Question Step 3: Form A Hypothesis Step 4: Test The Hypothesis By doing experiments Step 5: Analyze The Results Step 6: Draw Conclusions Step 7: Communicate results Scientific Method (In List Format) Use independent variables when you test your hypothesis by doing experiments (see step 4 above)

(Variables and Controls) SPI 0807.Inq.1 (Variables and Controls) Notes Science Experiments In an experiment you should conduct multiple trials How many? More is better! Experiments should include independent variables, dependent variables, constants, and controls.

An Independent Variable SPI 0807.Inq.1 (Variables and Controls) Notes Science Independent Variables In an experiment… …you should only test for ONE key thing at a time When you repeat the experiment… …only change this ONE key thing This one thing is called… An Independent Variable Also know as….the manipulated variable

The Independent Variable SPI 0807.Inq.1 (Variables and Controls) Notes Science Memory Trick Independent variable begins with the letter “I” So remember the letter “I.” Imagine yourself doing the experiment., and ask yourself… “What ONE thing will I change when repeating the experiment?” That one thing will be… The Independent Variable Also know as….the manipulated variable

(Variables and Controls) Video Review SPI 0807.Inq.1 (Variables and Controls) Science Let's take a moment to watch and discuss a video-song about this topic Link: Variables Song by Mr. Edmonds

What is the independent (manipulated) variable in this example? Example: You decide to do an experiment to determine the reason certain soft drinks are more popular that others. You suspect that the popularity of the drinks is connected with the amount of sugar found in them. You decide to use Dr. Pepper, Coke, Pepsi, and Barq's root beer. You first determine how much sugar each drink contains. Then you get 6 students to do a blind taste test with all 4 drinks. What is the independent (manipulated) variable in this example? In other words, what is the one thing being tested for or changed? The independent variable is the type of soft drink

Exit Ticket – SPI 0807.Inq.1 Independent Variables A student designs an experiment to determine how surface type affects the amount of force needed to roll a ball 20 meters. What is the independent variable?   the lengths of the surfaces C. the type of surfaces used the force needed to roll the ball D. the type of ball chosen

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amount of phosphorus used per plant. C. type of each plant used. A student wants to test how the concentration of phosphorus in a fertilizer affects plant growth. In designing this experiment the independent variable would most likely be the...?   amount of phosphorus used per plant. C. type of each plant used. height each plant grows after given fertilizer. D. type of phosphorus used. Students want to determine which type of plant will best survive in a hot, dry environment. They place four different types of plants in identical pots, and put all of the plants by the same large window. They give each plant the same amount of water every day. Which of these is the independent variable for the students’ experiment? amount of water C. type of plant health of plant D. amount of sunlight 3 4

Dependent Variables

(Variables and Controls) Also called "Responding Variable" SPI 0807.Inq.1 (Variables and Controls) Notes Science What Is A Dependent Variable? Often called the "responding variable" because it is the response to the factor that was previously introduced These are the results that you observe after you introduced the independent/manipulated variable In other words, anything that "changes on its own" while the experimenter is observing it will be a… Dependent Variable Also called "Responding Variable"

Example: A scientist is conducting an experiment to test how sunlight affects plant growth. She places one corn plant 1 meter away from a sunlamp. She places one corn plant 2 meters away from a sunlamp. She places one corn plant 3 meters away from a sunlamp. Corn plant 01 Corn plant 02 Corn plant 03 The independent variable is the distance from the sunlamp What is a dependent variable in this example? HINT: What is the response to the distance from the sunlamp? A dependent variable is the plant growth

Example: A student conducts an experiment with ten 8th grade students. He uses 3 similar types of sour candy in a series of four trials. (Sour Patch Kids, Sour Skittles, and Warheads) He gives 1 piece of candy to each student and records their facial expressions to estimate how sour each candy is. The independent variable is the type of sour candy What is a dependent variable in this example? HINT: What is the response to the different types of candy? A dependent variable is their reaction (facial expressions)

The independent variable is the type of glue Example: A student conducts an experiment to determine which type of glue works best for attaching two pieces of regular writing paper together. She places 2g of glue on each sheet of paper, and then uses a spring scale to measure how much force it takes to pull the sheets apart. She uses 3 types of Elmer’s glue in a series of experiments. Liquid-washable Glue Stick-washable Glue Stick-nonwashable The independent variable is the type of glue What is the independent (manipulated) variable in this example? In other words, what is the one thing being tested for or changed? What is a dependent variable in this example? HINT: What is the result from using the different types of glues? Dependent variable-how much force to pull apart the paper

What is the independent (manipulated) variable in this example? Example 05: A student conducts an experiment to determine which ink color in ballpoint pens will last the longest before running out. She copies text from her science book. She copies the same text over and over. She writes at the same speed. The room temperature remains the same. She writes on the same kind of paper each time. She uses 3 ink colors in 3 ballpoint pens in a series of experiments. (1) Black ink pen, (2) Blue ink pen, (3) Red ink pen) What is the independent (manipulated) variable in this example? In other words, what is the one thing being tested for or changed? The independent variable is the color of the ink What is a dependent variable in this example? HINT: What is a result from using the different color inks? A dependent variable is how long the ink lasts.

Exit Ticket – SPI 0807.Inq.1 Dependent Variables Mrs. Logan designs an experiment to determine how surface type affects how far a ball will roll across a variety of surfaces. What is the dependent variable?   the lengths of the surfaces C. how far the ball rolls the type of surface D. the type of ball chosen The picture below illustrates an experiment designed by Mrs. Pope to test plant growth using potted green bean sprouts placed in front of a window. Which of these is the dependent variable in this experimental design? how tall each plant grows C. the height of each plant’s ceramic pot different types of light sources D. the distance from the light source 2

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Controls

(Variables and Controls) What Are Control Experiments? SPI 0807.Inq.1 (Variables and Controls) Notes Science What Are Control Experiments? An experiment to verify the results of another experiment using the same conditions except for one factor or variable An experiment separated from the main experiment where the independent variable being tested cannot influence the results. Simply remove the independent variable entirely or replace it with a neutral independent variable. Also called control groups

Experiment Notes Control Experiment (Fruity Pebbles Example) SPI 0807.Inq.1 (Variables and Controls) Notes Science (Fruity Pebbles Example) Experiment Does eating a sugary cereal make children hyperactive? Every day for a week have 3 children eat a bowl of Fruity Pebbles. Then observe their energy level for the next two hours. Manipulated/Ind Variable: -the Cereal Responding/Dep Variable: their behavior This is your main experiment. Can also be called the experimental group Next do a control experiment (see next slide)

Notes Experiment Control Experiment (Fruity Pebbles Example) SPI 0807.Inq.1 (Variables and Controls) Notes Science (Fruity Pebbles Example) Experiment Does eating a sugary cereal make children hyperactive? Every day for a week have 3 children eat a bowl of Fruity Pebbles. Then observe their energy level for the next two hours. Manipulated/Ind Variable: -the Cereal Responding/Dep Variable: -their behavior Do a control experiment by simply removing the independent variable entirely or replace it with a neutral independent variable. Option 01: Repeat the experiment exactly except this time don't give the children any cereal at all. Option 02: Repeat the experiment exactly but give them a bowl of cereal that does not contain any sugar.

Example: A scientist is conducting an experiment to test how sunlight affects plant growth. She places one corn plant 1 meter away from a sunlamp. She places one corn plant 2 meters away from a sunlamp. She places one corn plant 3 meters away from a sunlamp. The independent variable is the distance from the sunlamp Corn plant 01 Corn plant 02 Corn plant 03 Do a control experiment by simply removing the independent variable entirely or remove its affect control experiment-place one other corn plant in a dark room

Notes Experiment Control Experiment (Energy Drink Example) SPI 0807.Inq.1 (Variables and Controls) Notes Science Experiment If you consume an energy drink before running will it enable you to run faster? On 3 different days at the track, consume one can of energy drink. (Day 1: Monster, Day 2: Red Bull, Day 3: Rock Star) Then run 30 meters as fast as you can. Record the time it takes you to run that distance. (Energy Drink Example) Manipulated/Ind Variable: -type of energy drinks Responding/Dep Variable: -how fast you run This is your main experiment. Can also be called the experimental group Next do a control experiment (see next slide)

Notes Experiment Control Experiment (Energy Drink Example) SPI 0807.Inq.1 (Variables and Controls) Notes Science Experiment If you consume an energy drink before running will it enable you to run faster? On 3 different days at the track, consume one can of energy drink. (Day 1: Monster, Day 2: Red Bull, Day 3: Rock Star) Then run 30 meters as fast as you can. Record the time it takes you to run that distance. (Energy Drink Example) Manipulated/Ind Variable: -type of energy drinks Responding/Dep Variable: -how fast you run Do a control experiment by simply removing the independent variable entirely or remove its affect control experiment-run one more time without an energy drink or have a glass of water instead.

Exit Ticket – SPI 0807.Inq.1 Controls

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Dependent Independent Text Sent/ Data Used Cell Phone Bill The amount of gas you have Hours of sleep per night Cell Phone Bill How far you can drive Waking up on time

Independent Dependent Number of XBOX achievements earned How many tardies you have How fast you drive Who scores more points Temperature Number of Whoopers Bottles of water drank Higher gamer score Loss of locker for 1 week Time it takes to drive somewhere Result of a football game Wearing shorts or long pants Total calories and fat Number of bathroom breaks

Variables and Controls Day 3

Paper Airplanes Question: Does changing the size of the paper affect how far a paper airplane flies?

1. Start off by preparing three pieces of paper with the same ratio of height and width.   *8.5×11 inches *7×9.5 inches *5.5 x 8 inches.

2. Fold the papers into the same design for all three 2. Fold the papers into the same design for all three.  The design doesn’t really matter.

3. Use the same force to throw the airplanes 3. Use the same force to throw the airplanes. Measure how far each one flies.  (You may want to do multiple trials, although that is not the point of the lesson.)  Record data

Variables and Controls Day 4

Identify Independent Variables, Dependent Variables, and Controls EXPERIMENT 1 Group Review: One time when Ms. Ryland went to the grocery store she bought all the types of microwave popcorn that the store had. With these types of popcorn she conducted an experiment. Scientific Question: Does the amount of butter on the popcorn kernels affect the number of kernels that pop? Review the hypothesis that you created in the hypothesis practice. Identify the IV, DV, and constants that would be necessary to conduct this experiment AND have the results be VALID. Independent variable: ________________________________________________________________________ Dependent variable: _________________________________________________________________________ Constants: _________________________________________________________________________________ __________________________________________________________________________________________

Identify Independent Variables, Dependent Variables, and Controls EXPERIMENT 2 Group Review: Kelly proposes the idea that the marble would travel at a faster pace if it is rolled down the longer slide. This discussion leads to the following scientific question. What happens to the speed a marble travels when the height of a ramp is changed? Review the hypothesis that you created in the hypothesis practice. Identify the IV, DV, and constants that would be necessary to conduct this experiment AND have the results be VALID. Independent variable: ________________________________________________________________________ Dependent variable: _________________________________________________________________________ Constants: _________________________________________________________________________________ __________________________________________________________________________________________

It’s Your Turn On your own, complete the Independent Variable, Dependent Variable, and Control activity.