is more open to bias than direct observation, however. Of particular
concern)are social desirability effects, which occur when some people
try to present themselves in a favorable light (for example, by saying that
they exercise more than they actually do). Still, the survey method has
produced many important results. For example, before (Masters and
Johnson conducted their research on the human sexual response, most of
the available information on how people behave sexually (as opposed to
how laws, religion, or society said they should behave) came from
