What's the issue?
The questions to be addressed to respondents have to be structured in a way that will enable smooth communication between interviewers and respondents, retaining the neutral character of the interviews and facilitating the response task.
The questionnaire should be structured into sections that address particular issues or topics, and that follow one from the other. The first questions should be particularly interesting/easy to answer.
It should begin with a brief introductory text, continue through a number of easy warm-up questions, and only ask the more difficult to answer questions afterwards. Finally, close with the routine demographic questions.
Provide transitional statements in moving from one set of questions to the next, to give a conversational tone to the interview and to help the respondents to follow the shift from one topic to the next. This contributes to the perception of the questionnaire as a 'coherent whole'.
The introduction is of critical importance for establishing rapport with child respondents in particular.
In each set of questions, the movement should be from general to specific questions.
The question order has some effect on response error. Thus, a researcher needs to decide which questions will come first in the questionnaire, the question sequencing and the use of transition statements.
Pitfalls to avoid
One can make children uncomfortable by asking from the very beginning questions that require them to use a lot of effort to answer. Also problematic is the inclusion of topics and issues which are addressed by one question only (i.e. without follow ups), diminishing the reliability of the collected data.
Fowler, F. J. (1993). Survey Research Methods. (2nd edn.). Newbury Park; London; New Delhi: Sage Publications.
A researcher's experience
In semi-structured interviews it often happens that the children/adolescents are inspired to talk about something (by association during the interview topics and comments from others) and my experience is that it is important to pursue these directions and then make sure to get back on track. Even if the new direction regards something the interviewer planned to discuss at a later point it is best to follow the inspiration of the interviewees - then the interviewer may always follow up at the planned point. This is an exhausting strategy as the interviewer has to be really alert and good at keeping the overview. But it pays (Gitte Stald, Denmark).