Case Study 1.4

Social Psychology
Instructor:  Susan Boland  

This case study assignment requires that you apply information about research methods from Chapter 2 of the textbook.  Read the case study carefully and answer the six questions in detail.  Follow the instructions for case study assignments distributed in class.  A copy of the instructions is also on reserve in the library.  If you have any questions about the case study, please ask. 

Case Study 1.4 (30 points):  Facial expressions and mood 

     Janet was required to conduct a study as a final project in her research methods course.  She was interested in the relationship between facial expressions and emotion.  She wondered whether people's facial expressions are good indicators of their emotional state.  She had two ideas for such a study.

     Her first idea was to observe people in a public place, such as the mall, the school cafeteria, or maybe the university library. She would first observe a person's facial expression.  Janet planned to rate the facial expression on a 1-5 scale.  Negative facial expressions would be assigned a low number and positive facial expressions would be assigned a higher number.  She would then ask the person to complete a short questionnaire about his or her current mood.  Mood is rated on a scale of 1 to 10, the lower the score the more negative the mood, the higher the score the more positive the mood. Janet wanted to determine whether a link existed between the two variables, facial expression and mood.

     Her second idea was to try to influence the mood of students she recruited from Introduction to Psychology classes to participate in her study.  Each student would be given one of two passages to read. Half the students would read a description of a funeral, whereas the other half read a description of a birthday party. Janet would videotape the students as they read the passage, and she would rate their facial expressions on the same scale used in her first study.

 1)      One of Janet's ideas uses a correlational design and one uses an experimental design. First briefly
       describe each type of research design.  Next identify each study idea as correlational or experimental. 
       Finally, explain the basis for your identification.  In other words, explain what makes one of her study
       ideas a correlational design and the other an experimental design.  

2)      Suppose Janet carries out her first study and observes and records individuals' facial expression and current mood.  What relationship would you expect Janet to find between the variables?  Is the relationship positive or negative? Explain your answer.  If Janet discovered a strong relationship between the rating of facial expression and the rating of mood, can she conclude that mood causes facial expression?  Explain your answer.  Give at least one alternative explanation for a relationship between the facial expressions and mood.  

3)      In your own words, define independent variable.  What is the independent variable in Janet's second study? How does Janet plan to manipulate this variable in her study? Suggest a different way Janet could manipulate her independent variable.  That is, devise a different operational definition of the variable. 

4)      What is the dependent variable in Janet's hypothesis?  You should define the term dependent variable in your answer.  How does Janet plan to measure her dependent variable? Suggest a different way Janet could measure her dependent variable. 

5)      Her instructor tells Janet that she must randomly assign students to the conditions in her second study.  What is random assignment? (Take care not to confuse random sampling with random assignment.)   Explain why it is important to use random assignment and describe how random assignment works. 

6)      Compare Janet's two studies.  Describe one advantage and one disadvantage of the design she uses in her first study (e.g., observation and survey).  Also describe one advantage and one disadvantage of the design she uses in her second study.  If you had to choose one of these studies, which would you choose and why?