Allowing respondents not to answer questions

Respondents must generally answer all questions that are displayed during the interview. If they click Next without selecting or entering an answer an error message is displayed and the interviewing program waits for the question to be answered. There are a number of situations where this behavior is undesirable, typically:

▪You want to allow respondents not to answer certain questions. In this situation you want to display the question but allow the respondent to click Next without choosing an answer.

▪A question’s response list has been filtered so that it is empty (see Filtering categorical response lists). In this case the interviewing program recognizes that the question is now irrelevant and skips it automatically.

▪A question’s response list has been filtered so that it contains just the special No answer, Don't know, and Refused responses. In this situation you will not want to display the question but will want to code it as unanswered.

To allow a question to be unanswered for any reason, place the following statement in the routing section somewhere before the question is asked:

where Qname is the question’s name.

To allow all questions to be unanswered, type:

This is worth considering if the script contains only a few questions that must be answered, as you can reverse the setting just for the questions that must be answered.

Setting MustAnswer to False is sufficient to deal with questions or compound items with empty response lists, and with block, compound, loop, or page items that have no sub-questions (see Repeated questions and More than one question per page for information about these item types) but it is not sufficient for the other scenarios. In these cases you will need either to include the special na response in the response list or to define a default answer for the question. Questions that do not have either of these settings will still require respondents to answer them regardless of their MustAnswer flag.

If a response list contains an na response and the question has MustAnswer set to False, the interviewing program does not display the na response, but will use it whenever the respondent clicks Next without choosing an answer. This is the same as having MustAnswer set to True and displaying the na response for the respondent to select.

The following example illustrates these two options. The questions are defined in the metadata section as follows:

Siblings1 "Do you have brothers and sisters?" categorical [1..1]
{
  Yes,
  No,
  NoAnswer "" NA
};
Siblings2 "How many brothers and sisters do you have?"
long [0..10];

The routing statements are:

Siblings1.MustAnswer = "False"
Siblings1.Ask()
Siblings2.MustAnswer = "False"
Siblings2.Response.Default = 0
Siblings2.Ask()

Both questions allow the respondent to click Next without giving an answer. Siblings1 has an na response which the interviewing program will not display but which it will set as the response if none is given. Siblings2 has a default response value defined in the routing section, so any respondent who click Next without entering a number at this question will have their answer set to 0.

Note The two options apply equally to all response types and are not restricted to the response types shown in the example. You can set a default response for any type of question, and you can use na, whether or not it is hidden, with any type of question.

MustAnswer should only be used with boolean response lists that have a default answer specified or that contain a codes section defining categorical responses such as No Answer. If you use MustAnswer with a simple boolean response list, the interviewing program will always select False if the respondent does not answer the question.