Double Negative

A double negative refers to the use of two negatives in one statement or question. In questionnaire design, this is almost always a situation to be avoided. A double-negative usually creates an unnecessary amount of confusion in the mind of the respondent and makes it nearly impossible for the researcher to accurately determine what respondents were agreeing or disagreeing to.

Such a question can increase item nonresponse by increasing the percentage of respondents unable to understand the question. A more insidious problem is an increase in the number of responses from people who have misunderstood the question and responded based on that misunderstanding. Both item nonresponse and misunderstanding contribute to the type of survey error know as measurement error.

Sometimes the questions sound sufficiently confusing that ...