Problem
Colony Collapse Disorder - Developing a Hypothesis
Honeybees play an important role in agriculture, by pollinating at least 90 different species of food plants, worth about 15 billion dollars in the U.S. alone. As a result, beekeeping or apiculture, is a multi-million dollar business. However over the last year, honey bee populations are crashing (Colony Collapse Disorder) with hives dying off in less than a week, without an obvious cause. Ian Limpkin a senior researcher in the Epidemiology (infectious disease) Department of Columbia University's Mailman School of Public Health believed the cause to be a pathogen (virus, bacteria or fungus) of some sort. Use the information given to answer the following questions.
A. What is the hypothesis (Hint, it is already given)?
B. Help Dr. Limpkin design an experiment to test this hypothesis. Identify the dependent and independent variable as well as which group is the control and experimental group. Be sure you can explain how you are going to conduct the test and predict what the results will be if they support the experiment. You are not to create the data for your results section.
C. If your hypothesis is to be supported, what should the data indicate? Specifically speaking, what should the results show between the two groups?
D. If your hypothesis is disproven, what should the data indicate? Specifically speaking, what should the results show between the two groups?
Male Pattern Baldness Experiment - Identifying Variables
Suppose you work for a lab that develops pharmaceutical products. Your research division has stumbled across a new drug that you believe cures male pattern baldness. Before you can start selling the drug, you must demonstrate to the U.S. Food and Drug
Administration that the drug is effective.
1. What is the question being asked?
2. What is the hypothesis (the more specific, the better)?
You design an experiment with 500 men who have been diagnosed with male pattern baldness. They are divided up into two groups, group A men receiving the drug while group B men receive a placebo, a drug that is known not to effect baldness. The drug is referred to as the experimental (independent) variable, since this is what is being tested. As a hint, the hypothesis will usually identify the experimental variable of a study.
In this study, the men receive the drug or a placebo once a day. All of the men will have the number of hairs per square inch of scalp measured in a clinic once per week. The number of hairs per square inch will be the dependent variable since this variable depends on the effectiveness of the experimental variable. The dependent variable is also what we use to determine if the experimental variable is actually acting according to the hypothesis and the data collected will usually tell what the dependent variable is.
Men in group A belong to the experimental group, since they received the experimental variable. Men in group B belong to the control group. The control group is important since it gives the researchers something to compare the experimental group to. For instance, if the men in the experimental group were shown to have hair growth, then that would indicate that the hypothesis was supported and the drug grows more hair. However, if the control group also grew hair, then something in the environment besides the drug was responsible for hair growth.
A. Define dependent and experimental (independent) variables?
B. Compare and contrast the experimental and control group.