January 6th Objectives: Turn-in data folders. Review Independent and Dependent Variables.

SPI 0807.Inq.1 (Variables and Controls) Imagine that an engineer has designed a rocket backpack that will enable a person to fly like superman. However, he needs to test it to make sure it is safe enough for people to use, and he wants you to help him with these experiments. 1) Write about some careful ways to test this rocket backpack. 2) Describe some of the scientific tools you would use. 3) Decide how many tests you would conduct, and explain why.

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) Variables and Controls in Experiments  Used with the scientific method  Use independent variables when you test your hypothesis by doing experiments (see step 4 above) SPI 0807.Inq.1 (Variables and Controls) Notes Science

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

Experiments: In an experiment you test or measure a quantity and/or quality of something. SPI 0807.Inq.1 (Variables and Controls) Notes Science Example: Measuring Quantity: Scientists could be testing a new cell phone battery to determine how long it will last when you are text messaging. Example: Measuring Quality: Scientists could be testing new IPod ear buds to determine if they are more comfortable or not.

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… Independent Variables SPI 0807.Inq.1 (Variables and Controls) Notes Science Also know as….the manipulated variable

What is an independent variable? The one thing YOU change each time you duplicate an experiment Here is our simple memory trick to help you with this.  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… SPI 0807.Inq.1 (Variables and Controls) Notes Science Also know as….the manipulated variable

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

The independent variable is the type of soft drink Example 01: 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?

Example 02: A scientist is conducting an experiment to test how sunlight affects plant growth. The independent variable is the distance from the sunlamp which is connected with the amount of sunlight.  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 01Corn plant 02Corn plant 03 What is the independent (manipulated) variable in this example? In other words, what is the one thing being tested for or changed?

Example 03: A student conducts an experiment with ten 8th grade students. He uses 3 similar types of sour candy in a series of 4 trials. (Sour Patch Kids, Sour Skittles, and Warheads) He gives 1 piece of candy to each student and records their facial expressions to determine how sour each candy is. The independent variable is the type of sour candy What is the independent (manipulated) variable in this example? In other words, what is the one thing being tested for or changed?

Example 04: A student conducts an experiment to determine which type of glue works best for attaching two pieces of regular writing paper together. The independent variable is the type of glue 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. What is the independent (manipulated) variable in this example? In other words, what is the one thing being tested for or changed? Liquid-washable Glue Stick-washable Glue Stick-nonwashable She uses 3 types of Elmer’s glue in a series of experiments.

Example 05: A student conducts an experiment to determine which ink color in ballpoint pens will last the longest before running out. The independent variable is the color of ink 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) 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. What is the independent (manipulated) variable in this example? In other words, what is the one thing being tested for or changed?

Variables Practice