Controls, Variables, Simpsons and SpongeBob, OH MY! Scientific Method Controls, Variables, Simpsons and SpongeBob, OH MY!

Testable Questions In order to solve many scientific questions, scientists form what are called TESTABLE QUESTIONS What would be an example of a testable question? Most testable questions have: An Manipulated (independent) variable & A Responding (dependent) variable

Testable Questions Does changing the height of the ramp affect the speed of the car going down the ramp? A testable question can be answered through research or experimentation. It is not an opinion.

The SINGLE item that will be changed in an experiment Variables Manipulated/Independent Variable The SINGLE item that will be changed in an experiment Height of the Ramp Ramp 1 Ramp 2 Ramp 3

Speed of the Car Variables Responding/Dependent Variable It is what changes BECAUSE of the manipulated/ independent variable The item that will be measured in an experiment Speed of the Car

Manipulated Variable Responding Variable Testable Question #1 Manipulated Variable Does changing the height of the ramp affect the speed of the car going down the ramp? Responding Variable

Other parts of a TESTABLE question Controlled Variables (a.k.a Constants) The conditions that are kept the same (unchanged) in an experiment Same car Same ramp surface Same surface the car travels on All of these things help to make the test FAIR and Reliable!

Control Group Does watering a plant with coffee make the plant grow faster? What are we testing? (the independent variable?) If coffee increases growth How are we going to know if coffee makes a plant grow faster? NEED TO HAVE A COMPARISON- the CONTROL GROUP What would the control group be?? Watering with PLAIN WATER

Controls and Variables Practice Ready for some clicker questions???

Does the type of bubble gum chewed affect the size of the bubble Does the type of bubble gum chewed affect the size of the bubble? Identify the INDEPENDENT VARIABLE Type of bubble gum Size of the bubble 20 of 30

What will the dependent variable measure for the gum question? Does the type of bubble gum chewed affect the size of the bubble? What will the dependent variable measure for the gum question? Type of gum Time gum is chewed Size of bubble Number of bubbles 20 of 30

Does watering a bean plant with gatorade affect the growth of the plant? Identify the DEPENDENT VARIABLE Watering a bean plant Growth of the plant 21 of 30

The plant watered with gatorade The plants watered with water Does watering a bean plant with gatorade affect the growth of the plant? For the bean plant question, what would be the CONTROL for this experiement? The gatorade The plant watered with gatorade The plants watered with water The water Response Grid 21 of 30

Krusty Krabs Breath Mints Mr. Krabs created a secret ingredient for a breath mint that he things will “cure” the bad breath people get from eating crabby patties at the Krusty Krab. He asked 100 customers with a history of bad breath to try his new breath mint. He had 50 customers (Group A) eat a breath mint after they finished eating a crabby patty. The other 50 (Group B) also received a breath mint after they finished the sandwich, however, it was just a regualr breath mint and did not have the secret ingredient. Both groups were told that they were getting the breath mint that would cure their bad breath. Two hours after eating the crabby aptties, thirty customers in Group A and ten customers in Group B reported having better breath than they normally had after eating crabby patties.

Which people are the control group? Mr. Krabs Group A Group B Why is this the control group??? Group B didn’t get the breath mint with the special ingredient. 19 of 30

What is the independent variable? Bad breath Special breath mint Regular breath mint Clean breath 20 of 30

What is the dependent variable? Bad breath Special breath mint Regular Breath mint Fresh breath 20 of 30

What should Mr. Krab’s conclusion be? The special breath mint helped cure bad breath The special breath mint didn’t cure bad breath There is no way to know if the special breath mint worked 13 of 30

Why do you think 10 people in group B reported fresher breath? They were confused They thought they had the special mint They were given a mint They never had bad breath 0 of 30

SpongeBob Clean Pants SpongeBob noticed that his favorite pants were nto as clan as they used to be. His friend Sandy told him that he should try using Clean-O detergent, a new laundry soap she found at Sail Mart. SpongeBob made sure to was one pair of pants in plan water and another pair in water with the Clean-O detergent. After washing both pairs of pants a total of three times, the pants washed in the Clean-O detergent did not appear to be any cleaner than the pants washed in plain water.

What is the problem that SpongeBob wanted to investigate? Why are his pants dirty? Will plain water clean his pants? Does Clean-O detergent work? How many washes does it take to clean his pants? 0 of 30