Surveys

A Stat 113 instructor announces a study session to be held the night before a test.
The instructor lists the students who attended the session and compares their scores to the remaining Stat 113 students’ scores.
OBSERVATIONAL or EXPERIMENTAL??

• Observational

• Experimental

Which type of sampling?
Student organization looking to get signatures for a petition camp out in front of
Class of 1950 Lecture Hall.

• Convenience

• Stratified

• Random

• Systematic

Select three students from a class to receive ice cream by putting all the students names in a hat and picking out three names randomly.

• simple random

• convenience 

• cluster

• systematic

Select three female students and three male students to receive ice cream by putting all the men names in one hat and all the women names in a different hat and picking out three names from each hat.

• stratified

• cluster

• simple random

• convenience 

In Fall 1995, the BBC in Britain requested viewers to call the network and indicate their favorite poem.

• convenience

• random

• cluster

• systematic

Divide the class into four groups (freshman, sophomore, junior and senior) and take a random sample of two students from each group.

• stratified

• cluster

• random

• convenience

Priceline.com randomly e-mails a Customer Satisfaction Survey for certain transactions done on its site in which customers choose to either respond or not.

• convenience

• random

• stratified

• systematic

At a birthday party, teams are chosen by putting everyone’s name into a jar, then choosing names for each team.

• simple random

• convenience

• systematic

• cluster

To test the quality of a river's water, samples of the water would be taken from multiple places in the river, on different dates and at different times of the day. All of the samples would be numbered with the numbers entered into a table. As numbers are chosen from the table, quality tests are run on the chosen sample.

• simple random

• stratified

• cluster

• systematic

For a study, psychologists assign numbers to all volunteers for the trial. A number table is used to assign volunteers to the control group and to the four test groups.

• simple random

• convenience

• systematic 

• cluster