Q. In your 2009 report “Growing Old in America,” the words “older adult” and “middle-aged” are used along with age groups (e.g., respondents ages 65 and above). In other Pew Research reports, age cohorts are named as Baby Boomer, Silent Generation and so forth. Why does the Pew Research Center use these terms for older adults, instead of the words “senior” or “elderly”?

Your examples refer to two different kinds of studies. In some reports, we present data on age cohorts, also called generations. These are groups of people who share a specific set of birth years. The Baby Boomers are perhaps the best known example of an age cohort. This is a generation born in the years following World War II (typically limited to 1946-1964). Another generation we have reported on is the Millennials, the country’s youngest adults (we define them as adults born after 1980). Our typical generational analysis will compare the attitudes and characteristics of a generation not only with other generations but also with themselves using data from surveys conducted years earlier.

In other reports, we are simply comparing different age groups at one point in time. In these reports, we use labels commonly associated with the stage of life in which the group is located. Admittedly, we aren’t fully consistent in how we label different age groups, occasionally using “seniors” interchangeably with “older adults” and other synonyms. We do try very hard to avoid the use of the term “elderly,” since many people find the term objectionable, and there is little agreement on how old one must be to be elderly.

Scott Keeter, Director of Survey Research, Pew Research Center