BackAn experiment is performed to test the effects of a new drug on attention-deficit/hyperactivity disorder (ADHD). The experimenter identifies 320 people ages 7 to 44 with ADHD to participate in the experiment. The subjects are divided into equal groups according to age. Within each group, subjects are then randomly selected to be in either the treatment group or the control group. What type of experimental design is being used for this experiment?
Identify the sampling technique used in each study. Explain your reasoning.
A journalist asks people at a campground about air pollution.
Identify the sampling technique used in each study. Explain your reasoning.
A study on attitudes about smoking is conducted at a college. The students are divided by class (freshman, sophomore, junior, and senior). Then a random sample is selected from each class and interviewed.
Which technique used in Exercise 7 could lead to a biased study? Explain.
Determine whether the study is an observational study or an experiment. Explain.
Researchers conduct a study to determine whether a medication based on fish oil known as omega-3 carboxylic acids is effective in reducing the risk of cardiac events in people already at risk. In the study, 13,078 patients are randomly chosen to receive either omega-3 carboxylic acids or a placebo of corn oil daily. Researchers compare the number of cardiac events of the two groups over similar follow-up periods of time. (Source: American Heart Association)
200 students volunteer for an experiment to test the effects of sleep deprivation on memory recall. The students will be placed in one of five different treatment groups, including the control group.
Explain how you could design an experiment so that it uses a randomized block design.
The items below appear on a physician’s intake form. Determine the level of measurement of the data for each category.
a. Temperature
b. Allergies
c. Weight
d. Pain level (scale of 0 to 10)
Determine whether the data are qualitative or quantitative, and determine the level of measurement of the data set.
Census Regions The four geographical regions of the United States recognized by the U.S. Census Bureau are listed.
Northeast, South, Midwest, West
Determine whether the data are qualitative or quantitative, and determine the level of measurement of the data set.
The top six final scores at the 2021 U.S. Women’s Figure Skating Championships are listed. (Source: NBC Sports)
232.61 215.33 214.98 213.39 199.95 178.89
What is the difference between a census and a sampling?
200 students volunteer for an experiment to test the effects of sleep deprivation on memory recall. The students will be placed in one of five different treatment groups, including the control group.
Explain how you could design an experiment so that it uses a completely randomized design.
Identify the sampling technique used, and discuss potential sources of bias (if any). Explain.
A student asks 18 friends to participate in a psychology experiment.
Identify the sampling technique used, and discuss potential sources of bias (if any). Explain.
Law enforcement officials stop and check the driver of every third vehicle for blood alcohol content.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement.
A double-blind experiment is used to increase the placebo effect.
Determine whether the statement is true or false. If it is false, rewrite it as a true statement.
The method for selecting a stratified sample is to order a population in some way and then select members of the population at regular intervals.