Discussion Questions

1. Discuss the characteristics of a rate in light of the definition presented in chapter 2. Describe some specific research problems and/or study designs that are particularly appropriate for the use of rates. Are there any research problems and/or study designs where the use of rates may be inappropriate? Are you satisfied that the risk set (i.e., the population at risk) adequately and concisely captures the risk of exposure to some extent? Why or why not?

2. Identify some research situations where the use of bivariate tables is not appropriate. What do these situations have in common and how do researchers deal with them (e.g., by recoding our variables or finding another way to organize our data altogether)?

3. The table below displays employment status characteristics for three categories of Hispanics in the United States. Discuss why it is often useful to display multiple frequency distributions at once. How may doing this enrich the information being presented, and subsequently enhance the argument of the author(s)?

Employment Status of the Foreign-Born Population by Race and Hispanic Ethnicity, 2010 (percentages)

Employment Status

White Non-Hispanic

N = 7,363

Black Non-Hispanic

N = 2,898

Asian Non-Hispanic

N = 8,072

Hispanic

N = 17,162

Employed

56.2%

65.3%

61.1%

62.8%

Unemployed

4.5

9.3

4.8

8.0

Not in labor force

39.3

25.4

34.2

29.2

Total

100%

100%

100.1%

100%

Source: U.S. Census Bureau, 2012 Statistical Abstract of the United States, Table 589.

4. What is the difference between a bar chart and a histogram? Why are the bars separated in the former but not in the latter? What types of variables are appropriate for each? As a class, discuss a classification scheme for deciding what type of graphic device to use for the following types of variables: discrete, dichotomous, nominal, ordinal, interval/ratio, and continuous. Is there any additional information that would be useful to consider toward helping students to avoid confusing the two?

5. Which type of chart would we most likely use in a study that examines the rate of AIDS incidence over the past 30 years? What are the reasons for using this type of chart?

6. Describe some of the other ways we could graphically display the information conveyed in the charts in chapter 3? Which graphs are easier to understand? Which take more time to understand?

7. If you want to illustrate the number of applicants for four different jobs, which form would you use (pie, line, or bar chart)? Why?