1. "Scientist A designed a research study to examine the effect of water temperature on coral bleaching. 100 samples of coral were harvested (50 from Australia's Great Barrier Reef and 50 from the Florida Keys) and brought to the lab, where they were placed in carefully-controlled aquariums. Salinity, pH, light, and water depth were the same in both groups. The control group had a water temperature of 25C, while the experimental group had a water temperature of 40C. Coral samples from the Great Barrier Reef in Australia were placed in the experimental group, while samples from the Florida Keys were placed in the control group. After three weeks, there was a much higher rate of bleaching in the experimental group."

Identify the weakness in this experiment. Pick the best answer.

-Randomization

-Control

-Compare

-There was no weakness. This is an example of a well-designed experiment.

Use one of the possible answers in the previous question (which you did not select):

Using 100 pieces of coral is an example of:

-Control -Replication -Compare -Randomization

2. "Scientist B designed a research study to examine the effect of a new medication on a rare genetic disorder causing muscle weakness in young boys. Two boys who are identical twins and both with the disorder were enrolled in the study. One was randomly assigned to the experimental and the other was assigned to the control group. The participant in the experimental group received an injection of the new medication once weekly for six weeks. The participant in the control group received an injection of a harmless vitamin solution once weekly for six weeks. The participants were not told whether they were in the experimental or control group. Over the course of the study, Scientist B tracked the muscle strength of each participant. At the end of the six weeks, the boy in the treatment group showed a slight improvement in muscle strength. The boy in the control group showed the typical decreases in muscle strength."

Identify the weakness in the study. Pick the best answer:

-Replication

-Randomization

-Control

-Compare

Use one of the possible answers in the previous question (which you did not select) :

Making sure that both participants are as similar as possible and therefore limiting potentially confounding/lurking variables is a good example of:

-Control -Replication -Compare -Randomization

3. "A university professor wants to know if class time affects students' grades. In the coming semester, she will be teaching an 8am class and a 3pm class of the same subject. In each of her classes she will have 100 students in each class."

Briefly describe an experiment that could answer this question. Make sure to attempt to include the idea characteristics of a well designed experiment: Replication, Randomization, Control and Comparison. Specificallyexplain how each characteristic is included in your experiment or why it is not (practical or ethical reasons).