rather than taking an additive focus like most studies which attach individual features to a base textual
message, a subtractive focus might be useful. 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.