Experimental Design & Graphing

What is a hypothesis?

• Something that changes in an experiment
• Something that stays the same in an experiment
• A prediction about what will happen in an experiment
• Tests for what it says it tests for

Choose a hypothesis for the given observation: The pitcher noticed that when he ices his shoulder between innings, he pitches an average of 8 miles faster on each pitch.

• If the pitcher throws the ball harder, his pitches are faster.
• If the pitcher doesn't ice his shoulder between innings, his pitches are slower.
• If the catcher stands further back, the pitcher throws faster.
• If the pitcher ices his shoulder between innings, his pitches are faster.

Tags

NGSS.MS-PS1-4

NGSS.MS-PS3-5

What is a VALID experiment?

• An experiment that has something that changes.
• An experiment that tests for what it says it tests for.
• An experiment that can be repeated over and over with similar results
• An experiment that has data.

Tags

NGSS.MS-LS1-5

NGSS.MS-PS1-2

Janel tested to see which cat food her cat liked best by putting out all of the types of food one night and looking at it a few hours later. The dog was in the house as well as the cat, and she didn't watch the food the entire time. She didn't measure it, and she hadn't fed the cat for a few days before the bought all of the food. Is this a valid experiment, even by "backyard science" standards?

• Yes
• No

Terrance wanted to test how well he can hide vegetables in food because his little sister was a picky eater. He decided to hide carrots in cookies as his first test. He made sugar cookies, half with carrots and half with orange food coloring, and otherwise they were the same. He served them at a family party (25 people, everyone ate one of each) without people knowing there was a difference and asked questions about them after. Is this a valid experiment, even by "backyard science" standards?

• Yes
• No

What makes an experiment RELIABLE?

• It comes to work on time
• It tests for what it says it tests for
• You can run the test over and over and get the same or similar results
• Chemical reactions

Tags

NGSS.HS-LS1-3

Check the examples of experiments with results that are most likely to be reliable. (Two answers)

• A new lemonade was test marketing at a concert. Three people were asked if they liked the lemonade and only one said yes. It was determined that the formula was bad.
• A new orange-peel based flea treatment was tested on 25,000 cats. Of those, 23,768 of them had fewer fleas after 3 days. The control group of 10,000 cats, which received no flea treatment, showed no decrease in fleas after 3 days.
• A candy company tested a new super sour candy in their test market, a small city of 15,000, by mailing out free samples. When they called 500 homes, they got average to favorable results from 385 of the calls, and decided to make the candy.
• A new growth serum was to be tested on lettuce plants. One plant was given the serum and it grew very large. The company decided to market it as a miracle growth serum for all plants.
• A hair company tested a new shade of hair dye on 5 people in Hong Kong and it didn't make a difference in their hair. The company decided not to market it anywhere in the world.

Tags

NGSS.MS-ETS1-3

NGSS.MS-PS1-2

Which part(s) of the experimental design do you need to think carefully about to keep your experiment VALID? (2 answers)

• Constants
• Repeated trials
• Control group
• Large sample size

Which part(s) of the experimental design do you need to think carefully about to keep your experiment reliable? (Two answers)

• Repeated trials
• Large Sample size
• Constants
• Control Group

Tags

NGSS.MS-PS2-5

NGSS.MS-PS3-4

What are variables in an experiment?

• The things that stay the same in an experiment.
• A prediction about what will happen in an experiment.
• The things that change in an experiment.
• The things that you gather using your senses.