Survey cheating is no surprise really when people are being incentivised with cash and/or prizes etc. There are some very effective methods to identify cheaters. Successfully removing them from the final data is imperative to ensure the highest quality results.
When the final data is in, review how long it has taken each respondent to complete the survey. Any outliers to the average length of interview (LOI) should be reviewed and removed where necessary.
Open ends should be reviewed to ensure quality feedback has been provided. Where feedback doesn’t make sense or is non-existent, respondents should be reviewed and removed where necessary.
If a respondent has straight-lined – answering a series of rating questions with the same answer, the remainder of their responses should be reviewed along with the length of interview to ascertain whether they should be removed from the data.
Using dummy brands/trick options within a survey can be a good way of identifying if a respondent is cheating, or indeed if they are paying attention and providing quality feedback. Again, each case should be reviewed.
If you have screening questions in your survey, survey cheats can try to make sure they qualify by selecting all options in a multiple response question. Again, dummy brands/trick responses can be used to help identify these.