Parts of an Experiment

1. Parts of an Experiment

2. Review of Vocabulary • Independent Variable: This is what CHANGES in the experiment • Dependent Variable: This is what is being MEASURED • Control: The basis for comparison. “Business as usual” • Constants:Aspects of the experiment that are kept the same in ALL trials.

3. Experiment 1 It’s Science Fair time!! You decided to test miracle grow on sun flowers as your science fair project. In Pot A, you decide to put in the miracle grow. In Pot B, you do not use the miracle grow. You use the same amount of water, sunlight, and dirt in each pot. In 4 months, you measure the height of each flower to see which is taller.

4. Experiment 2 A researcher is studying the effect of sleep on aggression, thinking that less sleep will lead to more aggression. She has some people sleep 6 hours per night, some people sleep 3 hours per night and some people sleep as much as they want. The researcher made sure that every participant sleeps on the same kind of mattress. She then monitors aggressive behavior during basketball games among participants.

5. Experiment 3 A researcher is curious to find out what effect classical music has on people’s level of relaxation (as measured by heart rate). He suspects that listening to classical music will make people feel more calm and relaxed. He lets one group listen to classical music for one hour. He lets another group sit in a quiet room for one hour (i.e they hear no music). After one hour, he monitors the heart rate of each participant to measure their level of relaxation.

6. Experiment 4 A student wanted to test how the mass of a paper airplane affected the distance it would fly. The paper airplane was tested by itself to determine how far it would fly. Next, paper clips were added before each test flight. As each paper clip was added, the plane was tested to determine how far it would fly. The same paper airplane was used each time.

7. Experiment 5 A math teacher wanted to know if using calculators during a test would speed up the time it took to take a test. Two groups of students were tested to compare their speeds working math problems. Each group was given the same problems. One group used calculators and the other group computed without calculators. The teacher used a stopwatch to time how long it took each student to finish their test.

8. Experiment 6 • An experiment was performed to determine how the amount of coffee grounds could affect the taste of coffee. The same kind of coffee, the same percolator, the same amount and type of water, and the same perking time were used for each test. In the first test, no coffee grounds were used.

9. Experiment 7 • A researcher in the army wanted to do a study to find out if adding a new tire tread would affect the breaking distance of an Army jeep. One army jeep was outfitted with the new tire tread and another jeep used the original tire tread. The researcher compared the time it took each jeep to break after it reached a speed of 55mph. The same road was used to test each jeep.