Qualitative researchers try to gain an insider's perspective on the subject. For example, a researcher studying teen pregnancy would go beyond gathering demographic data and would ask young mothers what they think about teen pregnancy.
Qualitative research relies heavily on interviews, and researchers skilled in establishing rapport, trust and a safe environment are more likely to uncover useful information. Socioeconomic differences such as age, gender and education level can also impact results. For example, a teen mother might be more open about her view of motherhood when talking to a female researcher.
Scientists and others doing qualitative research often study people who live in other countries or speak another language. The World Health Organization gives an example of using local interpreters for a qualitative study of tropical diseases in Tanzania. Since these translators were not professionals, it is impossible to assess the quality of the translation. Cultural differences can impact qualitative research when the question suggests something unintended to the respondent.
Writers at Health.gov state that "some participants tend to express views that are consistent with social standards and try not to present themselves negatively. This social desirability bias may lead respondents to self-censor their actual views, especially when they are in a group setting." This factor might come into play at unexpected times. For example, a personal trainer in a focus group about healthy eating habits is unlikely to share that she eats cookies every night.
To conduct an interview, it is sometimes necessary to take respondents out of their natural environment, and this may change their behavior. For example, a woman who was in a violent relationship will probably present very differently when she is at a shelter versus when she is living at home with her abusive partner.