Experiment Design Make this title on the next page of your notebook. Copy AT LEAST the things shown in green.

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Carmel Willis
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1 Experiment Design Make this title on the next page of your notebook. Copy AT LEAST the things shown in green.

2 Create these skeleton notes: Experiment Design Stands for Stands for Stands for

Background Info Mr. Harris was an awesome athlete in high school.

Consequently, he spent lots of time in the gym and locker room.

3 Background Info Mr. Harris was an awesome athlete in high school. He earned 12 sport letters and started for the varsity team on nearly every sport. Consequently, he spent lots of time in the gym and locker room. He would develop raging skin infections red, itchy, raised bumps and peeling skin all over his toes and feet. These infections were Athlete s Foot caused by a fungus on skin that loves to grow in damp, warm conditions. It also spreads rapidly on shower floors an can live in shoes. Yikes!

The Remedy One time, he was SO sick of itchy

for feet Special infused socks Spray for feet

4 The Remedy One time, he was SO sick of itchy feet that he went to the store, spent $40 and bought every product they had for itchy feet: Special shoe insoles Powder for shoes Cream for feet Special infused socks Spray for feet Special ant-fungal soap He used every remedy for 3 days

5 The $40 Question After 3 days, his feet were cured no more red, itchy bumps! After football practice one day, his mom asked, How are your feet? He replied that they were fine now. Then she asked, What did the trick? What did he reply?

6 Experimental Design He didn t know what worked to kill his fungal infection because he tested too many cures at once. He did NOT use a fair test method. What SHOULD he have done? Change only ONE thing at a time

7 Second Try The next time his athlete s foot problem flared up, he knew what to do. He focused on just one cure. He decided to try rubbing antifungal cream onto the red bumps. He faithfully applied the cream twice per day to both feet. After 3 days, he was cured! Did he use a fair testing method this time?

8 Experimental Design In a good experiment, we always compare two or more groups. A control group is the name we give to this set of trials which are used as a baseline or a comparison. Most experiments have a control group, but not all. Compare two groups

Third Try This time, he was sure he knew what to do when the old red, itchy bumps came back. He used one foot as the control group, and did not put any remedies on that foot.

9 Third Try This time, he was sure he knew what to do when the old red, itchy bumps came back. He used one foot as the control group, and did not put any remedies on that foot. On the other foot, he tested only one remedy at a time. What does he know about the remedy if If both feet are still red? If both feet are cured? If the control foot is red and the remedy foot is cleared?

Experimental Design If one application of Tinactin cream cures the spots on one foot, can we declare to the world that, Tinactin cream is the best Athlete s Foot remedy and should be

10 Experimental Design If one application of Tinactin cream cures the spots on one foot, can we declare to the world that, Tinactin cream is the best Athlete s Foot remedy and should be used by all!? Do we have any certainty in our results if we conduct only one trial? Do you think that drug manufacturers test their product only one time? Repeat at least three trials

11 Repeat after me Change only 1 thing at a time Compare 2 groups Conduct at least 3 trials (repeats of the experiment)

12 Experiment Vocabulary copy these into your notes under the independent variable (IV) dependent variable (DV) controlled variable (CV) control group hypothesis the one thing changed on purpose the measured outcome of the experiment the response something kept the same for all groups - constants the half of the experiment trials used for comparison a prediction of the outcome of an experiment based on prior knowledge

Show me that you know A snowboarder wants to know if waxing the bottom of her snowboard really makes a difference in her downhill speed, like she has heard.

13 Show me that you know A snowboarder wants to know if waxing the bottom of her snowboard really makes a difference in her downhill speed, like she has heard. She takes her board (with no wax on the bottom) and lets it slide down the kiddie hill three times, recording how long it takes each time and starting at the same spot each time. Next she puts wax on her board and lets it slide down the same hill three more times, recording how long it takes each time and starting at the same spot each time. What is IV? What is DV? What are CVs? Control? Hypothesis? Number of trials?

14 Show me that you know A snowboarder wants to know if waxing the bottom of her snowboard really makes a difference in her downhill speed, like she has heard. She takes her board (with no wax on the bottom) and lets it slide down the kiddie hill three times, recording how long it takes each time and starting at the same spot each time. Next she puts wax on her board and lets it slide down the same hill three more times, recording how long it takes each time and starting at the same spot each time. What is IV? What is DV? What are CVs? Control? Hypothesis? Number of trials? Waxing the snowboard Downhill speed board, slope, snow, temperature Board with no wax Wax will make board slide faster 3

Show me that you know A kid heard that hot water would freeze faster than cold water, but that just didn t make sense, so he decided to conduct an experiment.

15 Show me that you know A kid heard that hot water would freeze faster than cold water, but that just didn t make sense, so he decided to conduct an experiment. He took 3 Styrofoam cups and filled them with exactly 500 ml of tap water then he put 500 ml of steaming hot water into 3 more Styrofoam cups. He placed all 6 cups into the freezer and checked them every 10 minutes to see if the top had formed an unbreakable solid by trying to poke a straw to the bottom of the water. What is IV? What is DV? What are CVs? Control? Hypothesis?

16 Show me that you know A kid heard that hot water would freeze faster than cold water, but that just didn t make sense, so he decided to conduct an experiment. He took 3 Styrofoam cups and filled them with exactly 500 ml of tap water then he put 500 ml of steaming hot water into 3 more Styrofoam cups. He placed all 6 cups into the freezer and checked them every 10 minutes to see if the top had formed an unbreakable solid by trying to poke a straw to the bottom of the water. What is IV? What is DV? What are CVs? Control? Hypothesis? Temperature of water Time taken for water to freeze Amount of water, cup, freezer Tap water Hot water will freeze faster than cold water 3

17 Show me that you know You stay up at night reading with a flashlight and you want to know which batteries to buy to give you the most reading time. You have heard that Duracell is the best, but they are pricey! You buy two D batteries each of Duracell, Energizer, Rayovac and Kirkland brands. You get 4 identical flashlights out of your emergency kits and put one brand of batteries into each flashlight. You turn them all on at the same time one night in your room and wait to see which flashlight stays on the longest. What is IV? What is DV? What are CVs? Hypothesis? Did you conduct enough trials?

18 Show me that you know You stay up at night reading with a flashlight and you want to know which batteries to buy to give you the most reading time. You have heard that Duracell is the best, but they are pricey! You buy two D batteries each of Duracell, Energizer, Rayovac and Kirkland brands. You get 4 identical flashlights out of your emergency kits and put one brand of batteries into each flashlight. You turn them all on at the same time one night in your room and wait to see which flashlight stays on the longest. What is IV? What is DV? What are CVs? Hypothesis? Did you conduct enough trials? Brand of battery Time for battery to run out of electricity Flashlight, temperature, room, angle Duracell will last longest because the cost the most No, only 1 trial was conducted

19 Show me that you know Weber High s football team had a tough loss on Friday night! To cheer the guys up, one mom decided to wash all 40 of the team s sweaty, grass-stained pants and get them sparkling white. One pair belonging to the running back even had a little blood on it, so she pretreated those pants with Shout them put them all into commercialsized washers at the laundromat. She had always wondered which laundry detergent was the best so she washed half in Tide and the other half in Gain and dried all the pants for 35 minutes on high. What is the IV? What is DV? What are CVs? Was this a fair test? How many trials?

20 Show me that you know Weber High s football team had a tough loss on Friday night! To cheer the guys up, one mom decided to wash all 40 of the team s sweaty, grass-stained pants and get them sparkling white. One pair belonging to the running back even had a little blood on it, so she pretreated those pants with Shout them put them all into 2 commercialsized washers at the laundromat. She had always wondered which laundry detergent was the best so she washed half in Tide and the other half in Gain and dried all the pants for 35 minutes on high to see which pants would turn out the most stain-free. What is the IV? What is DV? What are CVs? Was this a fair test? How many trials? Brand of laundry detergent Whiteness of football pants (amount of stains) Amount of detergent, size of washer, water No, because one pair was pre-treated 20

Variables Worksheet. Find it: Class Website, Unit 6, #2a Open it: In Notability. Title it: H#, Last, First, Variables Move it: To Unit 6

Variables Worksheet. Find it: Class Website, Unit 6, #2a Open it: In Notability. Title it: H#, Last, First, Variables Move it: To Unit 6 Variables Worksheet Find it: Class Website, Unit 6, #2a Open it: In Notability Title it: H#, Last, First, Variables Move it: To Unit 6 2 IDENTIFYING VARIABLES 3 Learning Target Learning Target: I can understand