| This study investigated visual search for simple and complex geometric and pictorial point symbols displayed on light and dark smooth and textured map backgrounds. Group-administered tests asked subjects to count occurrences of target symbols. Efficiency of visual search was determined by analyzing subjects' self-recorded counts and times for accuracy and speed. Results for symbols indicate that simple geometric and pictorial symbols are easier to search, especially when their shapes differ considerably. In contrast, complex geometric and pictorial symbols differing only in minor details of shape or orientation are harder to search. Results for backgrounds show that high value contrast between symbol and background (e.g. black symbol on white ground) facilitates search, while low contrast (e.g. black symbol on dark gray ground) yields poorer results. Since subjects also found it harder to identify symbols displayed on textured backgrounds (e.g. aerial photograph, satellite image, or relief shading), visual noise is another background factor. |
