Many social, cultural, and behavioral phenomena pose measurement challenges to researchers. For example, multiple operational definitions have been used to assess education (Smith, 1995), political ideology (Knight, 1999), religiosity and religious fundamentalism (Hall et al., 2008; Kellstedt and Smidt, 1996), and race and ethnicity (NRC, 2004; Stephan and Stephan, 2000). Similarly, researchers who study LGBT populations face the challenges of defining sexual orientation and gender identity and developing procedures for operationalizing these constructs.
As explained in Chapter 2, sexual orientation is typically defined and measured in terms of three dimensions—behavior, attraction, and identity. Ideally, which of these dimensions is used in research is informed by a particular study’s research goals. For example, a study of HIV risk in gay men would appropriately focus on sexual behavior, whereas a study of experiences with hate crimes or housing discrimination might focus on sexual orientation identity (Herek et al., 2010). Although most adults exhibit consistency across the three dimensions (e.g., they are exclusively heterosexual or homosexual in their sexual behavior, attractions, and self-labeled identity), some do not. Whether a particular study categorizes the latter individuals as lesbian, gay, homosexual, bisexual, heterosexual, or something else will depend on which specific dimension of sexual orientation is measured in that study. In a study that measures sexual orientation in terms of same-sex attraction or sexual behavior with a same-sex partner, for example, the sample may include some participants who do not label themselves as lesbian, gay, or bisexual.
Not only do studies vary in which facet of sexual orientation they measure, but they also can differ in how they define each of the three dimensions operationally. The current lack of standardized measures contributes to the variability of population estimates and can make comparisons across studies difficult. For example, if two studies defined sexual orientation operationally in terms of sexual behavior but used different time frames for screening participants (e.g., if one study used the criterion of any same-sex sexual behavior during the past 12 months, whereas the other used any same-sex sexual behavior since age 18), they might reach different conclusions about the target population. Moreover, the samples obtained for both studies would exclude individuals who were not sexually active during the specified time period even if they experienced same-sex attractions or self-identified as lesbian, gay, or bisexual. This variability in the criteria for operationally defining sexual orientation may produce what appear to be inconsistent findings across studies. Although it may appear obvious, it is important to make the point that researchers should carefully evaluate the