Experiments are required to establish cause-and-effect relationships, but observational studies have their advantages too. In which situation would an observational study be preferred over an experiment?

When the study requires controlling and manipulating the study subjects

When the researcher wants to actively change the behavior of the study subjects

When the study aims to compare the effects of two or moretreatments

When it is unethical to assign treatments that may cause harm to the subjects

Experiments are required to establish cause-and-effect relationships, but observational studies have their advantages too. In which situation would an observational study be preferred over an experiment?

When the study requires controlling and manipulating the study subjects

When the researcher wants to actively change the behavior of the study subjects

When the study aims to compare the effects of two or moretreatments

When it is unethical to assign treatments that may cause harm to the subjects

Analyzing the results of rolling a fair die 100 times refers to which of these principles?

• A.)Control
• B.)Randomization
• C.)Treatment
• D.)Replication

Which of these statements is NOT true regarding a randomized block design experiment?

This design has an advantage of controlling for variables that might confound the response.

Subjects are randomly assigned to equal sizedblocks, then again randomly assigned to treatment or control within the block.

The sample is divided into blocks by an attribute,then randomly assignedto treatment or control.

Within blocks, subjects are randomly allocated to treatment and control groups.

Select the FALSE statement about completely random design.

Subjects are randomly assigned to a control group ora treatment group.

Completely random design is a quick and simple way to assign test subjects.

Completely random design is an effective way to ensure each group is representative of the larger population.

One or moretreatments may be addressed.

Which of these statements about a matched-pair design is FALSE?

• D.)Possible confounding variables are controlled by matching as many characteristics as possible.

This method helps to control for variables other than the one being studied.

After a matched pair is made, one subject is assigned to the control group, and the other to the experimental group.

Two distinct subjects are required for each pair.

Which of these statements about a matched-pair design is FALSE?

Possible confounding variables are controlled by matching as many characteristics as possible.

This method helps to control for variables other than the one being studied.

After a matched pair is made, one subject is assigned to the control group, and the other to the experimental group.

Two distinct subjects are required for each pair.

Which of these represents a blind experiment?

Asking a group of children to choose their favorite toy from a bin containing different toys

Asking a group of students about their favorite TV show from a list of eight TV shows

Asking a group of students to choose their favorite field trip location from a list of five field trip options

Asking a group of adults to compare the taste of coffee without revealing the names of the brands

Jennifer had a headache and was told she was given a headache medication,but it was really a sugar pill. Three hours later, she was asked if she felt better, and she agreed. How does the placebo effect apply in this situation?

Jennifer's headache would have gone away with or without medication.

The benefit Jennifer felt is dueto her belief in the treatment: Jennifer experienced relief because she believed she was taking headache medicine.

The benefit Jennifer felt is dueto the treatment since she also took a nap.

The benefit Jennifer felt was due to the medication.