Scientific Method Practice

Master the scientific method! Practice identifying variables, groups, and drawing conclusions.

Krusty Krabs Breath Mints Mr. Krabs created a secret ingredient for a breath mint that he thinks 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 customers (Group B) also received a breath mint after they finished the sandwich, however, it was just a regular 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, 30 customers in group A and 10 in group B reported having better breath. Independent Variable Secret Ingredient Dependent Variable Number of people with bad breath Experimental Group People who got the secret ingredient Control Group People who did not get the secret ingredient Constant Variables crabby patties What is the best conclusion for Mr. Krabbs to determine? The secret ingredient does help bad breath that customers get from crabby patties. The secret ingredient does not help with the bad breath that customers get from crabby patties. There is no change between the bad breath that customers got. SpongeBob Clean Pants SpongeBob noticed that his favorite pants were not as clean 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 wash one pair of pants in plain water and another pair in water with 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 washe din plain water. Independent Variable Type of detergent Dependent Variable how clean the pants are Experimental Group Pants washed with Clean-O Control Group Pants washed in plain water Constant Variable Washing Machine What conclusion should SpongeBob have? Clean-O is a the best detergent Clean-O is a worse detergent than plain water Clean-O has the same effect that plain water has Squidward's Symphony Squidward loves playing his clarinet and believes it attracts more jellyfish than any other instrument he has played. In order to test his hypothesis, Squidward played a song on his clarinet for total of 5 minutes and counted the number of jelly fish he saw in his front yard. He played his song for a total of 3 times on the clarinet then repeated the experiment using a flute and then a guitar. He also recorded the number of jellyfish he observed before he began playing an instrument. The results are shown in the data table. Independent Variable Type of instrument being played Dependent Variable Amount of jellyfish attracted Constant Variable Time each instrument was played