Chapter 1 Pre-Quiz Flashcards
When is a hypothesis considered scientific?
When it can be tested and is refutable.
What is the earliest step in the scientific process?
Developing a question based on an observation.
In a controlled experiment, which group receives the placebo?
The control group
In the studies of coffee and memory discussed, the independent variable is ___ and the dependent variable is ___.
Caffeine, memory
You conduct a clinical trial to test whether a new drug relieves the symptoms of arthritis better than a placebo. You have four groups of participants, all of whom have mildly painful arthritis. Each group receives a daily pill as follows: control (group 1) - placebo; group 2 - 15 mg; group 3 - 25 mg; group 4 - 50 mg. At the end of 2 weeks, participants in each group are asked to rate their pain. What is the independent variable?
The drug itself
When would you have the most confidence?
Randomized clinical trial with 15,000 subjects.
What is the importance of statistical analyses?
They can be used to determine whether any observed difference between two groups are real or a result of chance.
You conduct a clinical trial to test whether a new drug relieves the symptoms of arthritis better than a placebo. You have four groups of participants, all of whom have mildly painful arthritis. Each group receives a daily pill as follows: control (group 1) - placebo; group 2 - 15 mg; group 3 - 25 mg; group 4 - 50 mg. At the end of 2 weeks, participants in each group are asked to rate their pain. What is your next step?
Run a statistical analysis to determine if the difference is significant.
You are listening to a news report that claims a new study has found convincing evidence that a particular weight-loss product is much more effective than diet and exercise. What constitutes “convincing” evidence in this case?
Statistical tests showed significantly more weight loss in the participants who used the weight-loss product than those who relied on diet and exercise.
How can two different studies investigating the same thing come to different conclusions?
May had had different sample sizes
May have used different types of participants
May have used different amounts of caffeine
May have evaluated memory differently
Can epidemiologists who find a correlation between the use of tanning beds and melanoma in college-age women conclude that tanning beds cause skin cancer?
No, correlation is not proof of causation.
