Variables
The variable that is being measured in an experiment is called the __
Response variable
The specimen on which an experiment is being performed on (e.g. humans, rats, plants, etc.)
Test subjects
Medical reports of 360,000 men showed that those who were overweight or had high blood pressure had a higher risk of kidney cancer. What are the subjects?
Applying each treatment to more than one subject or conducting an experiment multiple times is called __
Replication
The variables that are being controlled are called __
Factors
The way in which subjects are placed into a treatment group.
Random assignment
Human participants in a study are called the __
Subjects
What are the 3 components of a good experimental design?
Control, replication, randomization
A "fake" treatment that looks just like the treatments being tested
Placebo
The combination of specific levels from all factors that the subjects receive in an experiment
Treatments
What is the difference between an observational study and an experiment?
Factors/variables are being controlled (altered) in an experiment
The subjects in a study are not told which treatment they are receiving
Single-blind experiment
The treatment group where nothing changes or placebo is given is called the __
Control Group
40 people suffering from insomnia participate in a month-long test to see if diet and exercise would help them sleep better. Half were assigned to special no-desserts diet and half to a normal diet. Half of the people in each group were assigned to an exercise program, while the others did not exercise. This made 4 treatment groups. What is the response variable?
Quality of sleep
Among a group of women aged 65 and older who were tracked for several years, those who had a vitamin B12 deficiency were twice as likely to suffer severe depression as those who did not. Is this an experiment or observational study?
Observational Study, because no treatments
Occurs when subjects respond positively to a “treatment” even though it is a fake, simply because they think they are getting the real treatment
The Placebo Effect
Why do we compare different treatment groups?
To see if a treatment actually works
A valid conclusion from an experiment
Cause-and-effect relationship between two variables
What is a valid conclusion to draw from an observational study?
That two variables are associated
When both doctors and subjects are unaware of the treatments that subjects are receiving.
Double-blind experiment