Tennessee SPI Objective: Design a simple experimental procedure with an identified control and appropriate variables. Notes Science Check for Understanding Design and conduct a simple experiment that includes an independent variable, a dependent variable, and controls. Essential Question(s) 1) What are controls in experiments? 2) What is the difference between constants and controls? SPI 0807.Inq.1 Variables and Controls Instructions for Students 1) View this PowerPoint presentation in slideshow mode. 2) You can find instructions about how to do this by doing a Google search or by searching YouTube. 3) After you have it in slideshow mode, press the right-arrow keyboard button to advance through the presentation. 4) If you need help, please communicate with your teacher. SPI 0807.Inq.1C Controls

What is a constant? Constants in Experiments constants are not they same as controls Chewing Gum Experiment Question: Which flavor of gum lasts the longest? Give ten 8 th grade students one piece of gum. Each piece of gum will have a mass of 3 grams. Have them chew it for ten minutes. Constants in this experiment: (stay the same each time) All students are 8 th graders. Use the same ten students each time. Mass of each piece is the same. Time (10 minutes) is the same. These are things in an experiment that remain exactly the same each time you repeat the experiment.

How to do a control experiment:  Just remove the independent variable entirely or replace it with a neutral substitute. What Are Control Experiments? Also called controls and/or control groups …An experiment separated from the main experiment where the independent variable being tested cannot influence the results. …an experiment to verify the results of another experiment using the same conditions except for one factor or variable.

Notes SPI 0807.Inq.1 (Variables and Controls) Science Control Experiment (Fruity Pebbles Example)  This is called the experimental group  Next do a control experiment/control group (see next slide) 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 sugary cereal Responding/Dep Variable: -their behavior

Notes SPI 0807.Inq.1 (Variables and Controls) Science Control Experiment (Fruity Pebbles Example)  Option 02: Repeat this experiment exactly but give them a bowl of cereal that does not contain any sugar. 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 sugary cereal Responding/Dep Variable: -their behavior Do a control experiment by removing the independent variable entirely and/or use a neutral substitute.  Option 01: Repeat this experiment exactly except this time don't give the children any cereal at all. Maybe give them eggs and toast instead.

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 Do a control experiment by removing the independent variable entirely or neutralize its affect. control experiment-place one other corn plant in a dark room Independent variable is the distance from the sunlamp. Dependent variable is how tall the plants grow.

Notes SPI 0807.Inq.1 (Variables and Controls) Science Control Experiment (Energy Drink Example)  This is the experimental group  Next do a control experiment (see next slide) 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. Manipulated/Ind Variable: -type of energy drinks Responding/Dep Variable: -how fast you run

Notes SPI 0807.Inq.1 (Variables and Controls) Science Control Experiment (Energy Drink Example) 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. Manipulated/Ind Variable: -type of energy drinks Responding/Dep Variable: -how fast you run Do a control experiment by removing the independent variable entirely and/or use neutral subsitute. control experiment- run at least one time without an energy drink or have a glass of water instead.

Independent variable …is the weights Dependent variable …is the height they reached What are the constants in this experiment?

Questions Science SPI 0807.Inq.1C Controls Independent variable …amount of carbon dioxide Dependent variable …height they grew What are the constants in this experiment?

Questions Science SPI 0807.Inq.1C Controls Independent variable …amount of sugar in the cereal Dependent variable …behavior after eating the sugary cereal What are the constants in this experiment?

Independent variable …type of grass Dependent variable …distance rolled What are the constants in this experiment?

Questions Science SPI 0807.Inq.1C Controls Independent variable …protein (steak) Dependent variable …energy level What are the constants in this experiment?