Types of Studies

Experimental or Observational?

Gilbert decided to study how parent's income affects children's performance on the SAT. He decided to collect information from a random sample and examined the relationship between parental income and SAT score.

• Experimental, nothing was imposed.

• Experimental, something was imposed.

• Observational, nothing was imposed.

• Observational, something was imposed.

Experimental or Observational?

Researchers examined health records of thousands of males and found that men who died of heart attacks tended to be shorter than men who did not.

• Experimental, nothing was imposed.

• Experimental, something was imposed.

• Observational, nothing was imposed.

• Observational, something was imposed.

Experimental or Observational?

Researchers compared vitamin D levels in blood samples from 150 US military personnel who have developed multiple sclerosis (MS) with blood samples of nearly 300 who have not. Those with the highest blood vitamin D levels had a 62% lower risk of MS than those with the lowest levels.

• Experimental, nothing was imposed.

• Experimental, something was imposed.

• Observational, nothing was imposed.

• Observational, something was imposed.

Experimental or Observational?

Researchers studied the herb black cohosh as a treatment for hot flashes caused by menopause. They randomly assigned 351 women 45-55 to 5 different treatments, one being the herb black cohosh. After a year, only the women group with estrogen replacement therapy had systems that improved.

• Experimental, nothing was imposed.

• Experimental, something was imposed.

• Observational, nothing was imposed.

• Observational, something was imposed.

Experimental or Observational?

In a test of 200 men and women, those with moderately high blood pressure did worse on tests of memory and reaction time than those with normal blood pressure.

• Experimental, nothing was imposed.

• Experimental, something was imposed.

• Observational, nothing was imposed.

• Observational, something was imposed.

Experimental or Observational?

Scientists exposed subjects to a cold virus, then gave the individuals either an herbal compound or a sugar solution known to have no effect on colds. Several days later they assessed symptoms and found no evidence of benefits associated with the compound.

• Experimental, nothing was imposed.

• Experimental, something was imposed.

• Observational, nothing was imposed.

• Observational, something was imposed.

Population?

Gilbert decided to study how parent's income affects children's performance on the SAT. He decided to collect information from a random sample and examined the relationship between parental income and SAT score.

• Children

• Parents

• Random Sample of students

• Random Sample of Parents

Sample?

Gilbert decided to study how parent's income affects children's performance on the SAT. He decided to collect information from a random sample and examined the relationship between parental income and SAT score.

• Children

• Parents

• Random Sample of students

• Random Sample of Parents

Population?

Researchers examined health records of thousands of males and found that men who died of heart attacks tended to be shorter than men who did not.

• Thousands of Males

• People

• Short Men

• Men

Sample?

Researchers examined health records of thousands of males and found that men who died of heart attacks tended to be shorter than men who did not.

• Thousands of Males

• People

• Short Men

• Men