Order effect

Order effects in market research surveys are well known and a variety of techniques are used to minimise any bias introduced by the order in which questions are asked. In qualitative research it is important to ensure that the order in which topics are introduced and discussed does not impact later question areas, often moderators are consciously introducing new elements during the discussion to understand whether and how specific issues impact opinion.

When using stimulus (concepts, adcepts, products) it is important to ensure that the material is rotated to minimise any bias caused by being evaluated first, second, third etc. Respondents will sometimes evaluate subsequent pieces of stimulus in comparison to the first; similarly, when asked to express a preference respondents will often recall the first or last piece of stimulus they were exposed to most readily, so it is important to iron out this bias with a rotation of stimulus across the interview, focus group or online bulletin board. In qualitative research a strict rotation may not always be possible due to limited scope of the study, and an informal rotation may be all that is practicable.