Market research glossary

The meaning of bias varies somewhat between qualitative and quantitative research. In qualitative research, bias tends to refer to personal preconceptions that influence decisions and judgements, or to the way in which unskilled moderators can influence the findings of the research through the way in which they conduct the discussion. In quantitative research, it commonly refers to sample bias, i.e. a situation where the sample of people who complete the survey does not accurately represent the population that the research is trying to assess. For example, people who are not confident in using a computer or smartphone will tend to be under-represented in online surveys. However, poor questionnaire design can also introduce bias into quantitative research.