Figure 1.24 shows an excerpt from the GSS codebook for one of its survey items. It shows the distribution of responses to the question over time, since the GSS first asked it in 1988.

a. What is this variable measuring?

b. How many categories does this variable have, and what are the labels for each of them? What are the numbers assigned to each category?

c. Between 1988 and 2016, how many respondents said that their sex partners had been both male and female?

d. What level of measurement is this variable? Explain how you know.

e. Which categories should be defined as “missing data”? Explain why.