A
subtractive focus would start with a realistic (from an
applications standpoint) multi-featured sign and
measure the relative effectiveness after removing or
changing a feature, e.g. whether a smaller or a noncoloured
sign D makes a difference. Also, additional
research might further improve sign D by evaluating
changes to the layout, wording and pictorials, and
could examine placement, long-term effects and
people’s attitudes toward the sign, elevator and stairs.