A maximum of six radio button options should be used per question.
Benefits of conformance
- Improved flow through the form.
Risks of non-conformance
- Increased cognitive load.
If more than six options are required in a form element a drop down select list should be used instead.
This requirement is based on psychological research that indicates humans have difficulty processing large sets of options. When more than six options are visible on the page the question will appear intimidating to users. In these cases a drop down select control should be used instead.
Recommended implementation: Six options are displayed using radio buttons.
Recommended implementation: More than six options are displayed using a drop down 'select' control.
Not recommended: Seven options are displayed using radio buttons.