We have been learning about how scientists set up and conduct experiments. In activity 4, we learned about controls, placebos, and how to look at and analyze data. In the Goldfish Respiration lab we used a control to compare the effects of cold on a fish's breathing. We also graphed our results using different sample sizes (our class and all classes) to gather evidence to support or disprove our hypothesis. And, on Monday, we looked at how insect repellents are tested and identified our Control, IV, and DV. The Goldfish lab was good example of a controlled experiment because we only tested one variable; Temperature. The Insect Repellent experiment was not a good example, because some of the test subjects drank Mountain Dew and others did not, which gave us bad data for 2 of the repellents.
Key words
- Independent Variable (IV) The variable that is changed or manipulated in an experiment. The cause.
- Dependant Variable (DV) The variable that responds to the change or manipulation in an experiment. The effect.
- Control- a standard used for comparison that is not changed in the experiment.
- Controlled Experiment- An experiment that tests only one variable at a time. .
Respond to both A and B by Tuesday 9/28
A) Use the link below to watch the Myth Busters video clip. Answer the following questions after watching the clip..
- What was the hypothesis (if and Then)
- What was the control?
- What was the IV
- What was the DV
- Do you think this was a controlled experiment? Provide evidence to support your answer.
B) I would like for you to redesign the insect repellent lab so that it will be a Controlled Experiment. Describe how you would change it, so that we only test one variable at a time.