Mark whichever side is the smaller set
Aliases: minority marking · mark optional · required indicator
What it is
Every field is required or optional. Marking the smaller set means: if eight of ten are required, mark only the two optional ones; if eight are optional, mark only the two required ones. People search for exceptions, they do not need a stamp on every row. The unmarked default should carry the meaning of the majority. This entry is only about which side is cheaper to scan. It is not about whether an asterisk needs a legend, and not about deleting optional fields when there are too many of them. How assistive technology hears required state is a different problem.
Why it happens
Visual search is faster for a rare feature. A screen full of red stars turns the star into texture; people stop using it to decide what can be skipped and assume everything is required, so the optional chance is wasted. Two stars make a clear search target: handle the marked ones first, treat the rest by the default policy. A second layer is default-as-meaning. Unmarked must stably mean “the majority side.” If some unmarked fields are required and some are optional, the default is hollow and people read helper text item by item; the marking system is not working. Choosing the minority reduces how many marks must be decoded. It does not change which items are actually required.
Studying it
Take the same form at two densities—mostly required versus mostly optional—and cross that with mark-required-only, mark-optional-only, and mark-both.
Independent variables: share of required fields, which side is marked, whether unmarked meaning is consistent. Dependent variables: actual skip rate on optional items, rate of filling optional items as if required, time to find the first exception, blocks at submit from missed required fields.
Lab participants are often told to “fill as much as you can,” which flattens skip rate; say explicitly that skippable items should be left blank. Fewer errors after adding stars is not evidence the correct side was marked—marking both also cuts misses, at the cost of slower scanning.
Where it stops holding
When required and optional are near half and half, there is no stable minority; marking one side makes the default wobble. Either change the field mix until one side dominates, or use words (“required,” “optional”) on both sides instead of a symbol. Where law or an accessibility audit demands a visible required mark on every required field, the required marks cannot be removed for the minority rule—but a second symbol on optional fields can still be avoided. Experts on internal forms who have learned the default will have their skip strategy broken for a while if the marked side flips.
Applying it
- Count required versus optional and put a visible mark only on the smaller side; leave the other side unmarked and state in one sentence at the top what unmarked means.
- Never let unmarked mean required on some rows and optional on others; when adding a field, assign it to the majority side first, then decide whether it needs a mark.
- Near a fifty-fifty split, do not invent a third symbol. Delete or move enough optional items that a minority reappears.
- Verify by asking someone uninvolved to mark, without submitting, “which can be left empty.” Errors clustered on the unmarked side mean the default failed; errors clustered on the marked side mean the mark became texture—you marked the majority. Flip sides and remeasure skip rate.