Experimental & Observational

A park ranger measures the change in height of all trees of a similar species and age over a month. Half of the trees are within a quarter of a mile from a large lake and half are further away. Is this an observational or experimental study?

• observational

• experimental

A park ranger plants 10 trees within a quarter of a mile from a large lake and 10 trees of a similar species and age further than half of a mile from the lake. He then measures the growth of all trees over a month. Is this an experimental or observational study?

• observational

• experimental

A zoo installs small "caves" in half of the wildcat cages. The caves provide shade and privacy for the animals and are just large enough to hold a wildcat that is lying down. The caretaker at the zoo then compares the sleeping habits of wildcats with "caves" in their cages to the sleeping habits of wildcats without them. Is this an observational or experimental study?

• observational

• experimental

A caretaker at a zoo records the sleeping habits of the wildcats at the zoo for a month. Is this an experimental or observational study?

• experimental

• observational

A researcher feeds one group of rats high-fat and high-calorie foods like cheesecake, bacon, and pastries. She feeds a second group of rats a normal, nutritious diet. For two weeks, the researcher records how many calories each rat eats daily, as well as how often it goes to its feeding bowl. She compares data from the one group to the data from the other and finds that the rats that eat the nutritious food get hungry less often and eat a smaller number of calories overall. What is the TREATMENT in this experiment?

• food given to the rats

• fatty foods

• nutritious foods

A researcher feeds one group of rats high-fat and high-calorie foods like cheesecake, bacon, and pastries. She feeds a second group of rats a normal, nutritious diet. For two weeks, the researcher records how many calories each rat eats daily, as well as how often it goes to its feeding bowl. She compares data from the one group to the data from the other and finds that the rats that eat the nutritious food get hungry less often and eat a smaller number of calories overall. What is the TREATMENT GROUP in this experiment?

• food given to the rats

• rats given fatty foods

• rats given nutritious food

A researcher feeds one group of rats high-fat and high-calorie foods like cheesecake, bacon, and pastries. She feeds a second group of rats a normal, nutritious diet. For two weeks, the researcher records how many calories each rat eats daily, as well as how often it goes to its feeding bowl. She compares data from the one group to the data from the other and finds that the rats that eat the nutritious food get hungry less often and eat a smaller number of calories overall. What is the CONTROL GROUP in this experiment?

• food given to the rats

• rats given fatty foods

• rats given nutritious foods

A college professor wants to know if students learn as well in an online class as in person. He decides to offer the same course both online and in a classroom. Students who sign up for the course are told they will be assigned to either class randomly. The professor then gives the same test to both classes and compares the scores. What is the TREATMENT in this experiment?

• online class

• class type

• in person class

A college professor wants to know if students learn as well in an online class as in person. He decides to offer the same course both online and in a classroom. Students who sign up for the course are told they will be assigned to either class randomly. The professor then gives the same test to both classes and compares the scores. What is the TREATMENT GROUP in this experiment?

• online class

• in person class

• class type

A college professor wants to know if students learn as well in an online class as in person. He decides to offer the same course both online and in a classroom. Students who sign up for the course are told they will be assigned to either class randomly. The professor then gives the same test to both classes and compares the scores. What is the CONTROL GROUP in this experiment?

• in person class

• online class

• class type