Social Psychology
Instructor:  Susan Boland

Case Study 1.7 

·          This case study assignment requires that you apply information from lecture and 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 in the course handout booklet.  A copy of the instructions is also on my web-page http://www.lhup.edu/sboland

·          Avoid quoting directly from the textbook -- write using your own words.  Information taken from the text, even if rewritten in your own words, must be credited to or cited to the textbook authors.  See the full instructions for more information about citing the text as a reference. 

·          If you have any questions regarding this assignment, please ask.  I am also happy to go over rough drafts of case studies with you.  If you wish me to review a rough draft, you must set up an appointment, allowing at least 20 minutes to go over the paper with me. Keep in mind that you may want to revise your paper after our conference, so you should have your rough draft ready well before the due date.

Case Study 1.7 (30 points):  Some Like it Hot - A Tale of Two Studies 

·         Janet and Dave are required to conduct a study as a final project in their research methods course.  They are both interested in the effect of weather on human social behavior.  Both decide to focus on one aspect of the weather, temperature, but choose different methods of study. 

DAVE:    During the past summer Dave worked at a construction job.  His boss was usually an easygoing guy.  Dave noticed, however, that the boss was more critical of his employees on hot days.  Dave hypothesized that environmental temperature affects how we perceive and evaluate other people.  Dave designed a study to investigate this hypothesis  He conducted the study in a small laboratory in which he could control the temperature by adjusting a thermostat.  He recruited volunteers to participate in the study by posting a sign-up sheet by the student mail boxes in his dorm.  When volunteers came to the lab, Dave randomly assigned them to either a comfortable temperature condition (70 degrees Fahrenheit) or to a high temperature condition (90 degrees Fahrenheit). All other environmental conditions (amount of light, humidity, noise) were kept constant across conditions.  He had each subject watch the same videotape of a male student who was practicing for a job interview.  Each subject then rated the student in terms his presentation and his overall personality.  Dave hypothesized that subjects would rate the student more negatively when they watched the tape in a room where it was 90 degrees than when it was 70 degrees.

 JANET:     Janet came up with her idea while she was watching an old rerun of the show "Miami Vice".  She remembered joking with friends from her home state of Wisconsin that there would never be a crime show called "Milwaukee Vice" because of the city's low crime rate.  Could the different crime rates in Milwaukee versus Miami be explained by differences in climate?  Janet wondered if  violent crime is related to temperature.  To discover if a link existed between temperature and crime, Janet conducted an archival study.  She went to the public library and looked at all the issues of the local newspaper for the year 2001.  From the daily paper she recorded the average temperature for each day and the number of violent crimes against persons listed in the police blotter column. (This may be stating the obvious -- but Janet recorded daily temperature and violent crime from the town where she currently lived.  Although her idea was inspired by a comparison of Miami and Milwaukee, she did not gather data from these cities.)

1.   a)    One of the studies uses a correlational design and one uses an experimental design. First briefly describe each
              type of research design.

b)    Next identify each study idea as correlational or experimental.

c)    Finally, explain the basis for your identification.  In other words, explain what makes one of
       the study ideas a correlational design and the other an experimental design. 

2.  a)   When Janet compares daily temperature to the number of violent crimes committed,
            what type of relationship would you expect Janet to find between the variables? 
            Do you think the relationship would be positive or negative? Explain your answer.

     b)   If Janet discovered a strong relationship between the daily temperature and violent crime,
           can she conclude that changes in temperature cause changes in criminal behavior? 
           Explain your answer.

     c)   Give at least one alternative explanation for a relationship between temperature and violent crime. 

3.  a)     In your own words, define independent variable. 

     b)    What is the independent variable in the experimental study?
            How is the variable manipulated in the study?

     c)     Suggest a different variable related to weather that a researcher could manipulate. 
             Devise an operational definition of the variable, that is, describe how it could be manipulated. 

4.   a)    What is a dependent variable?

      b)    What is the dependent variable in the experiment?  How is the dependent variable measured?      

      c)    Suggest a different dependent variable (must be a social behavior) that might be related to
             weather. How could you measure this variable?

 5.   a)    Dave randomly assigned volunteers to the temperature conditions.  What is random assignment?
              (Notice that question 6 also asks about random assignment.)
      b)    Describe a specific procedure Dave could use to randomly assign the participants.
      c)    Did Dave use a random sample of participants in his study (assume the population of
             interest is students at Dave's college)? 
             Define random sample and explain why Dave's sample does or does not meet the requirements.

6.   a)   What is internal validity? 

      b)   How does random assignment contribute to good internal validity?
           (One way to approach this question is to think what would happen if Dave didn't use random
            assignment.  Suppose he let participants choose for themselves whether to be in the 70 or
           90-degree room. How might this affect his results and the conclusions he could make about the
           effect of temperature?)

      c)   Besides random assignment, what else did Dave do in his study that improved internal validity?