Using different graphic characters and colour variation can help interviewers to navigate the questionnaire more easily, to follow skip patterns accurately, to reduce data entry errors and to reduce the chance that respondents will end the interview prematurely. All responses associated with a particular question should appear on the same page in order to ensure that none are missing and questions associated with the same theme or topic should be grouped closely together. This should be done without crowding the questions, which might cause some to be overlooked.