Station 1 Imagine that you are a farmer and have heard that various things affect the amount of milk produced by your cows. You wonder if music could have this effect. Hypothesis: If the amount of music played for the cows are increased, then the volume of milk they will produce will increase. Experiment: You selected three groups of cows that were all the same breed. You gave each group the same amount of food and kept them in the same grazing pasture for one week. Group Number of cows Amount of music played to cows (in minutes) A100 B 3 C 6 What is the independent variable? What is the control? Which of the following is a constant: A) music B) group A C) number of cows D) age of cows

Station 2 The following statement is a prediction or inference about an experiment. Read it and complete the questions that follow. Earthworms will grow longer in wet soil. What is the independent variable: a) amount of growth b) dampness of soil What is the dependent variable: a) worms will grow longer b) wetness of soil What would be an appropriate control group? Name two things that should be held constant for all groups of worms in the experiment?

Station 3 Sarah did an experiment to test the effect of temperature on seed growth. She set up three trays with the same soil and fertilizer. In each tray she planted 25 tomato seeds. Under tray #1, she placed a heat cord that stayed on during the whole experiment. Under tray #2 she placed a heat chord attached to a timer. It remained on only in alternating 8 hour intervals. Tray #3 received no heat cord. During the next two weeks the temperature in each tray was recorded, and the number of seeds that grew were counted daily. Sarah watered each tray with 100 milliliters of water every two days.

What is the dependent variable? a) amount of water b) number of seeds that grew c) fertilizer d) Temperature What is the independent variable? a) amount of water b) number of seeds that grew c) fertilizer d) Temperature The variables that were kept constant include: a) number of seeds and temperature b) temperature, water and number of seeds c) soil, fertilizer and temperature d) soil, number of seeds and water What is the control group?

Station 4 A new product is out on the market that is supposed to improve the weight gain of fish. The new special diet fish food needs to be tested against regular fish food. Three groups of fish were collected and fed over a two week period. They were all weighed at the end of the experiment. GroupType of food Average weight of fish after two weeks (in grams) ARegular fish food1 gram B Mix of regular and special food 3 grams CNew special food7 grams 1. What is the independent variable? 2. What is the dependent variable? 3. What is the control group in the fish experiment? a) group A b) group B c) group C

Station 5 Kent wanted to determine if adding water to a glass would change its pitch or tone when he tapped them with a fork. He set up four glasses and filled three of them with different amounts of water. He tapped each glass with a fork and listened to its pitch or tone. What would be a good control group for this experiment? What is his independent variable? What is his dependent variable?

Station 6 Rob wanted to find out which type of detergent best removes grass stains. What is his independent variable? What is his dependent variable? Name at least two constants he should have in his experiment. Write a procedure for his experiment (at least four steps).

Station 7 Kathy wanted to know if adding weight to the helicopter would affect how long it would stay in the air. She predicted that some weight would help stabilize the helicopter and keep it in the air longer than a helicopter without extra weight. What is Kathy’s hypothesis? What is her independent variable? What is her dependent variable? What can she use as a control group?