The 1KA tool has clearly defined missing values in the 'DATA' - 'Browse' tab. When it comes to the missing data of a certain question – item non-response – the 1KA tool uses the following labels:
- Value '- 1': the respondent (who otherwise filled in at least part of the questionnaire) did not answer a certain question, even though an answer was expected;
- Value '- 2': the respondent did not answer a question because it did not correspond to the IF condition (e.g. the question was only intended for women, hence men received a value of -2);
- Value '- 3': the respondent abandoned the survey before reaching this question;
- Value '- 4': the question was added after the respondent had already completed the questionnaire and was therefore unable to answer it;
- Value '- 5': the respondent did not answer any questions, thus the questionnaire was left empty.
The missing values of individual questions that are marked with the above negative numbers, need to be distinguished from the invalid values (e.g. ''I don't know,'' ''I refuse to answer,'' etc.), which also have negative values (-99, -98 ...). They must also be distinguished from the value of the unit statuses, which apply to the entire survey completed by a respondent.
You can also set or change the missing values manually in the 'EDIT' - 'Settings' - Missing values' tab.