The usefulness of the Basic Question - procedure for determining nonresponse bias in substantive variables: a test of four telephone questionnaires

The Basic Question Procedure (BQP) is a method for determining non-response bias. The BQP involves asking one basic question – that is, the question relating to the central substantive variable of the study – of those persons who refuse to participate in the survey.
  

The usefulness of the Basic Question Procedure for determining non-response bias in substantive variables – a test of four telephone questionnaires

Henk van Goor and Annemiek van GoorUniversity of Groningen

Non-response bias endangers the...