Question 11

In order to study corn output in all of Pennsylvania, a simple random sample of 10 farms is taken from every county in the whole state. This is an example of which type of sampling technique?

Question options:

1)	convenience

2)	simple random

4)	stratified

Question 12

To determine the public's position on taxes, people are selected from a crowd at the mall, a gas station, and a restaurant. This is an example of which type of sampling technique?

Question options:

1)	convenience

3)

cluster

4)	stratified

Question 13

All the names of Mansfield University's full-time students are put on a list and numbered. Then, 10 numbers are chosen randomly and with equal probability. These 10 people are then measured for their height to estimate the average height of a full-time Mansfield University student. This is an example of which type of sampling technique?

Question options:

1)	convenience

2)	simple random

Question 16

A college professor has a theory that a dose of 100 milligrams of caffeine can actually improve college students performance in their college courses. To test his theory, he chooses the 13 students in his Psychology 101 class who failed the first midterm and asks them to come to his office three times a week for individual tutoring. When the students come to his office, before the tutoring begins, he engages them in friendly conversation while at the same time pouring them a cup of strong coffee. (100 milligrams of caffeine per student.) After a month, he observes that 8 of the 13 students show significant improvement in their second midterm scores, 3 show some improvement, and 2 show no improvement at all. Based on this, he concludes that his theory about caffeine is correct. This study is best described as a

Question options:

2)	double blind experiment.

4)	squirrel falling out of a tree.

5)	none of the above.

Question 17

The students in the study were brought into his office and received individual tutoring. This might cause their grades to improve without the coffee in the first place. So the tutoring session itself is an example of

Question options:

2)	an experiment.

3)	a confounding variable.

4)	a clinical study.

5)	none of the above.

Question 18

0 / 1 point

The students in the study know they are in the study and the students who are not in the study know they are not in the study. For this reason (and this one only) the study may suffer from

Question options:

1)	the placebo effect.

2)	selective reasoning.

3)	selection bias.

Question 19

Two teachers decide to conduct an experiment on the effectiveness of a new teaching method. It is decided that the forty students that are registered for the class will be divided into two groups, with one being taught with the new method. On the first day of class the two teachers meet with the students. The teachers alternate picking students from the group until each of them has a class of exactly twenty people. This is an example of

Question options:

1)	a historically controlled experiment.

3)	a non-randomized controlled experiment.

4)	an observational study.

5)	Both a historically controlled experiment and an observational study.

Question 20

This is NOT the same as the last problem. :-) Two teachers decide to conduct an experiment on the effectiveness of a new teaching method. It is decided that the forty students that are registered for the class will be divided into two groups, with one being taught with the new method. On the first day of class the two teachers meet with the students. The teachers flip a coin to determine which class each student will attend. This is an example of

Question options:

1)	a historically controlled experiment.

2)	a randomized controlled experiment.

4)	an observational study.