Use these research scenarios to test your understanding of the different methods. After you’ve written down your answers, you can check the answers to see if you’re right.

1. Dr. A is studying whether babies can read emotional signals from their parents. His hypothesis is that parents’ facial expression will affect babies’ behavior. He has a group of 40 babies (with their moms). He has the moms draw numbers from a bowl, and this divides the group into two smaller groups of 20 babies/moms each.

Each baby is placed beside a new toy. In one group, the mom looks at the baby and smiles. In the second group, the mom looks at the baby and makes no expression.

Dr. A measures how close the baby crawls to the toy. He found that on average, the babies with the smiling mothers crawled closer to the toy than the babies with the expressionless mothers.

a. What is Dr. A’s research design?

b. What is the independent variable? What is the dependent variable?

c. What is the treatment condition? What is the control condition? 

2. Dr. B is studying the effects of massage. She questioned 200 people about their levels of anxiety and how often they have massages. She found a significant negative correlation between frequency of massage and anxiety.

a. What is Dr. B’s research design?

b. Draw the scatterplot of the findings.

3. Dr. C is studying attitudes toward gun control. Every two years, he chooses a random sample of 1,000 people in the USA. He sends them a set of questions, asking them to indicate how strongly they agree or disagree with various gun control proposals of the time. He has data going back 20 years. One of his findings is that after September 11^th, fewer people than ever before want gun control laws.

a. What is Dr. C’s research design?

b. What is Dr. C able to conclude? (What do the findings mean?)