Proposal
When configuring a Numeric Question optionally block the entry of negative numbers, e.g. by adding a button “Positive only”.
The data entry device would then prevent the entry of a minus sign (analogous to preventing decimal points with the “Integer” option), and prevent scrolling an entered value down to a negative number.
Affected subsystems
Designer
Interviewer
Tester
Surveys
I would use this feature in every future survey.
It is virtually impossible to have a survey without numeric questions about positive numbers like quantities, percentages, etc. which would benefit from it.
Alternatives
Adding a validation check.
What is the effect of this feature?
This feature would prevent the interviewer from entering negative numbers (usually by mistake), instead of only showing an error message by adding a validation check (which is the currently available alternative).
It would be:
- safer (because negative numbers are then impossible instead of undesireable)
- saving development time (needed to add validation conditions)
- saving interviewing time (errors would not occur, thus never needed to be corrected)
Compatibility
This would not affect any other part of the system or data.
Applicability
Would be useful to any questionnaire designer.